Daughter's math homework (1 Viewer)

[rolyaTy]

Gather around peoples....

In mathematics, another word for "negative" is "opposite".  Thus, -5 should be thought of as "the oppositive of 5" which means -5^2 is "the opposite of 5^2".

I must say, I have never thought of it like this. I will admit to this too....... My daughter had both problems right the first time, but as I was checking it over last night, I told her they were wrong. She questioned me a little bit, but was confused, and changed them.

When I got home from work today I faced one angry daughter as she got them both marked wrong, and those were the only 2 she had wrong.



Awesome discussion here tonight, and I'm learning a lot. I am going to make sure to have her read some of this stuff too.

I understand what he's saying there, but if the person meant to write negative five squared, that doesn't answer the question because the negative sign isn't meant to be the opposite of 5^2, but rather the opposite of five, squared.Maybe that's a good way to look at it. If you need a comma to convey your true meaning if you were saying it to someone, you need parentheses to show that...but if you read it without a comma (ie. the opposite of five squared) then you have to find out what 5 squared is first before you take the opposite.

So to me, a math equation doesn't have commas (parentheses) unless they are explicitly stated. So -5² + 4 x 2³ = is read "the opposite of five squared plus four times two to the third" and you apply the order of operations to how that is read.

cont.If you wanted to say (-5)² + 4 x 2³ , you'd have to say "The quantity negative five, squared, plus four times three to the third." If you don't say "The quantity" then you can read the word "negative" as "the opposite of" and you would have to square it first, according to PEMDAS. Saying "The quantity" is equivalent to using parentheses.

 

[Chase Stuart]

I put the original post up as my away message.For whatever reason, two people responded with "232" as their answer. One of them explained "if that is {[(-5)^2] + 4} x (2^3), then = 232". I copied the original first post, so I have no idea why he chose to use brackets and parenthesis like that.Another girl IMed me 37. I'm assuming this is because she's horrible at math (which is true), and not beacuse she found some other way to come up with an answer.

 

[Maurile Tremblay]

Here's the way I'd explain it.

-5^2

The five there has competing forces pulling on it from either direction. From the front, the minus sign wants to make it negative. From the back, the exponent sign wants to square it.

Which one happens first?

It's just a matter of doing the operations in the correct order. By convention, squaring comes before multiplication.

The trick is to realize that the minus sign is really a multiplication sign -- it is telling you to multiply by -1. (Alternatively, you could think of it as a subtraction sign, telling you to subtract it from zero. Either way, both multiplication and subtraction come after exponentiation.)

So with the 5 being hassled from both sides, the answer is to do the "^" before the "-" since the "^" is exponentiation and the "-" is multipliction (or subtraction), and exponentiation has priority.

Square the five first, then make the resultant figure negative.

 

[Serenity Now]

Honestly, I'm just stunned that -5^2 suddenly isn't what it was when I was in school.

 

[fairchild]

I put the original post up as my away message.

For whatever reason, two people responded with "232" as their answer. One of them explained "if that is {[(-5)^2] + 4} x (2^3), then = 232". I copied the original first post, so I have no idea why he chose to use brackets and parenthesis like that.

Another girl IMed me 37. I'm assuming this is because she's horrible at math (which is true), and not beacuse she found some other way to come up with an answer.

and these people made it through elementary school?

 

[Clayton Gray]

Gather around peoples....

In mathematics, another word for "negative" is "opposite".  Thus, -5 should be thought of as "the oppositive of 5" which means -5^2 is "the opposite of 5^2".

I must say, I have never thought of it like this. I will admit to this too....... My daughter had both problems right the first time, but as I was checking it over last night, I told her they were wrong. She questioned me a little bit, but was confused, and changed them.

When I got home from work today I faced one angry daughter as she got them both marked wrong, and those were the only 2 she had wrong.



Awesome discussion here tonight, and I'm learning a lot. I am going to make sure to have her read some of this stuff too.

I understand what he's saying there, but if the person meant to write negative five squared, that doesn't answer the question because the negative sign isn't meant to be the opposite of 5^2, but rather the opposite of five, squared.Maybe that's a good way to look at it. If you need a comma to convey your true meaning if you were saying it to someone, you need parentheses to show that...but if you read it without a comma (ie. the opposite of five squared) then you have to find out what 5 squared is first before you take the opposite.

So to me, a math equation doesn't have commas (parentheses) unless they are explicitly stated. So -5² + 4 x 2³ = is read "the opposite of five squared plus four times two to the third" and you apply the order of operations to how that is read.

In mathematics, "of" in a word problem means "multiplication".Ex:

What is 20% of ten?

"What" means "X"

"is" means "="

"20%" means "0.20" or "0.2"

"of" means "*"

"ten" means "10"

So "What is 20% of ten?" written as an equation is:

X = 0.2 * 10

X = 2, so two is 20% of ten.

Back to this:

So -5² + 4 x 2³ = is read "the opposite of five squared plus four times two to the third"

We have the word "of" (which means multiplication) between "the opposite" and "five", and we have the word "squared" (which is exponential) after "five".

Using order of operations, we know to calculate exponents before multiplication, so we take five squared before we take the opposite.

 

[Chase Stuart]

I put the original post up as my away message.

For whatever reason, two people responded with "232" as their answer. One of them explained "if that is {[(-5)^2] + 4} x (2^3), then = 232". I copied the original first post, so I have no idea why he chose to use brackets and parenthesis like that.

Another girl IMed me 37. I'm assuming this is because she's horrible at math (which is true), and not beacuse she found some other way to come up with an answer.

and these people made it through elementary school?

Law school friends. The 232 really surprised me; even more so than the 37, just because she's really bad at math.

But I guess the 232 does make some sense, no? Although I don't know why that would be anyone's first inclination.

 

[thatguy]

Why is this discussion still going on?  Move along people, there's nothing to see here.

This is the FFA. This thing may have another dozen pages in it.

Sadly, I fear you might be right.

 

[rolyaTy]

Gather around peoples....

In mathematics, another word for "negative" is "opposite".  Thus, -5 should be thought of as "the oppositive of 5" which means -5^2 is "the opposite of 5^2".

I must say, I have never thought of it like this. I will admit to this too....... My daughter had both problems right the first time, but as I was checking it over last night, I told her they were wrong. She questioned me a little bit, but was confused, and changed them.

When I got home from work today I faced one angry daughter as she got them both marked wrong, and those were the only 2 she had wrong.



Awesome discussion here tonight, and I'm learning a lot. I am going to make sure to have her read some of this stuff too.

I understand what he's saying there, but if the person meant to write negative five squared, that doesn't answer the question because the negative sign isn't meant to be the opposite of 5^2, but rather the opposite of five, squared.Maybe that's a good way to look at it. If you need a comma to convey your true meaning if you were saying it to someone, you need parentheses to show that...but if you read it without a comma (ie. the opposite of five squared) then you have to find out what 5 squared is first before you take the opposite.

So to me, a math equation doesn't have commas (parentheses) unless they are explicitly stated. So -5² + 4 x 2³ = is read "the opposite of five squared plus four times two to the third" and you apply the order of operations to how that is read.

In mathematics, "of" in a word problem means "multiplication".Ex:

What is 20% of ten?

"What" means "X"

"is" means "="

"20%" means "0.20" or "0.2"

"of" means "*"

"ten" means "10"

So "What is 20% of ten?" written as an equation is:

X = 0.2 * 10

X = 2, so two is 20% of ten.

Back to this:

So -5² + 4 x 2³ = is read "the opposite of five squared plus four times two to the third"

We have the word "of" (which means multiplication) between "the opposite" and "five", and we have the word "squared" (which is exponential) after "five".

Using order of operations, we know to calculate exponents before multiplication, so we take five squared before we take the opposite.

 

[Clayton Gray]

Where does one look for the answer to whether the "-" is treated as an operator or as part of a number?

We're right here, dude.

You're a hater. Negative numbers have as much right to individual identity as positive numbers. You're like a medieval land baron, forcing negative numbers to take the identity of their positive overlords. Or like some Third Reich demon lining up all the negative numbers to be branded with their negative operators for easy sorting into numerical Auschwitz.This kind of anti-negative bigotry will not be tolerated.

-5 is a self-contained unit and shall be afforded all of the rights and privileges of its positive brethren. Down with you, bourgeois pig, the proletariat are rising.

As the founding father of the negative post club, I can comfortably say you're barking up the wrong tree.

Isn't he going down the tree?

 

[Chase Stuart]

I haven't read the entire thread, but it seems that the mathematicians have determined the answer to be -25, which is contrary to what I thought. After reading the first few pages of "old math" (me) vs. "new math", I checked with my 8th grade honor student. He has been taught -5^2 = -5 * -5 = 25.

I hope he hasn't been taught that.

Why? Up until a few hours ago, that's exactly what I would have said. That's how I was tought.

 

[Clayton Gray]

Another girl IMed me 37. I'm assuming this is because she's horrible at math (which is true), and not beacuse she found some other way to come up with an answer.

of this girl please.TIA

 

[Clayton Gray]

Honestly, I'm just stunned that -5^2 suddenly isn't what it was when I was in school.

Oh, but it is.

 

[Brave Sir Robin]

I don't know if this has been pointed out but treating -5^2=-25 seems consistent with -(5-x) = -5+x by distributing the factor of -1. With that, I don't see how -5^2 could ever be seen as = 25.It's nothing I would put on a test though.

 

[thatguy]

I haven't read the entire thread, but it seems that the mathematicians have determined the answer to be -25, which is contrary to what I thought.  After reading the first few pages of "old math" (me) vs. "new math", I checked with my 8th grade honor student.  He has been taught -5^2 = -5 * -5 = 25. 

I hope he hasn't been taught that.

Why? Up until a few hours ago, that's exactly what I would have said. That's how I was tought.

He hopes this because based on the consensus here you son is wrong. Damn teachers, corrupting so many fine young minds.

 

[rolyaTy]

I haven't read the entire thread, but it seems that the mathematicians have determined the answer to be -25, which is contrary to what I thought.  After reading the first few pages of "old math" (me) vs. "new math", I checked with my 8th grade honor student.  He has been taught -5^2 = -5 * -5 = 25. 

I hope he hasn't been taught that.

Why? Up until a few hours ago, that's exactly what I would have said. That's how I was tought.

He hopes this because based on the consensus here you son is wrong. Damn teachers, corrupting so many fine young minds.

It's less that it's according to the consensus that he's wrong, and more according to the rules of mathematics i'd guess.

 

[fairchild]

I haven't read the entire thread, but it seems that the mathematicians have determined the answer to be -25, which is contrary to what I thought.  After reading the first few pages of "old math" (me) vs. "new math", I checked with my 8th grade honor student.  He has been taught -5^2 = -5 * -5 = 25. 

I hope he hasn't been taught that.

Why? Up until a few hours ago, that's exactly what I would have said. That's how I was tought.

I'm only 18 so I can't relate to you guys saying that -5^2 use to equal 25 but all through grade school, high school, and now college I have seen many problems like that involving no paranthesises and I think its always been pretty basic for everyone.

 

[thatguy]

I haven't read the entire thread, but it seems that the mathematicians have determined the answer to be -25, which is contrary to what I thought.  After reading the first few pages of "old math" (me) vs. "new math", I checked with my 8th grade honor student.  He has been taught -5^2 = -5 * -5 = 25. 

I hope he hasn't been taught that.

Why? Up until a few hours ago, that's exactly what I would have said. That's how I was tought.

He hopes this because based on the consensus here you son is wrong. Damn teachers, corrupting so many fine young minds.

It's less that it's according to the concensus that he's wrong, and more according to the rules of mathematics i'd guess.

Can't it be both? I take what is said in the FFA as gospel. Don't you?

 

[Chase Stuart]

I haven't read the entire thread, but it seems that the mathematicians have determined the answer to be -25, which is contrary to what I thought. After reading the first few pages of "old math" (me) vs. "new math", I checked with my 8th grade honor student. He has been taught -5^2 = -5 * -5 = 25.

I hope he hasn't been taught that.

Why? Up until a few hours ago, that's exactly what I would have said. That's how I was tought.

I'm only 18 so I can't relate to you guys saying that -5^2 use to equal 25 but all through grade school, high school, and now college I have seen many problems like that involving no paranthesises and I think its always been pretty basic for everyone.

I'm 22. We were never tought anything other than -5^2 is (-5)^2. It's said "negative five squared." I'm not sure why this is so surprising either way though; it's just the presumption we were tought; where you place the parenthesis tells you the correct way of doing it. The debate on the default rule might be interesting, but isn't very useful.

 

[rolyaTy]

I haven't read the entire thread, but it seems that the mathematicians have determined the answer to be -25, which is contrary to what I thought.  After reading the first few pages of "old math" (me) vs. "new math", I checked with my 8th grade honor student.  He has been taught -5^2 = -5 * -5 = 25. 

I hope he hasn't been taught that.

Why? Up until a few hours ago, that's exactly what I would have said. That's how I was tought.

He hopes this because based on the consensus here you son is wrong. Damn teachers, corrupting so many fine young minds.

It's less that it's according to the concensus that he's wrong, and more according to the rules of mathematics i'd guess.

Can't it be both? I take what is said in the FFA as gospel. Don't you?

Only if i'm rereading my own posts

 

[Charlie Murphy]

I wouldn't find fault in anyone for interprieting it as (-5)^2 since calculators interpreit it that way.

This is just not true. The standard at nearly all levels of teaching mathematics beyond sixth grade right now is the TI graphing calculator. Every one of them interprets -5^2 as -25 without exception.If you have another calculator that does otherwise, that doesn't make it correct. I'm not going to argue with you, I'm just telling you how it is in the profession. You're not going to find one degreed and certified mathematics teacher that works with exponents that will tell you different.

Interesting discussionI have a TI-68 calculator (from the early-mid 90s) and it has two buttons with "-". One is "minus", the other is "negative". Typing in "negative" five squared results in 25 (as it should). Typing in "minus" five squared results in ERROR. This is because one should not use the minus sign with integers and exponents without also using parentheses, otherwise the intended operation is unclear.

The most important thing here is this - All math teachers would do well to learn to write unambiguous formulas so that they don't confuse their students (and helpful parents), thereby "teaching" them that math sucks.

 

[rolyaTy]

I haven't read the entire thread, but it seems that the mathematicians have determined the answer to be -25, which is contrary to what I thought.  After reading the first few pages of "old math" (me) vs. "new math", I checked with my 8th grade honor student.  He has been taught -5^2 = -5 * -5 = 25. 

I hope he hasn't been taught that.

Why? Up until a few hours ago, that's exactly what I would have said. That's how I was tought.

I'm only 18 so I can't relate to you guys saying that -5^2 use to equal 25 but all through grade school, high school, and now college I have seen many problems like that involving no paranthesises and I think its always been pretty basic for everyone.

I'm 22. We were never tought anything other than -5^2 is (-5)^2. It's said "negative five squared." I'm not sure why this is so surprising either way though; it's just the presumption we were tought; where you place the parenthesis tells you the correct way of doing it. The debate on the default rule might be interesting, but isn't very useful.

I lost my grandfather in a misplaced parenthesis accident. Watch your mouth.

 

[Clayton Gray]

I haven't read the entire thread, but it seems that the mathematicians have determined the answer to be -25, which is contrary to what I thought.  After reading the first few pages of "old math" (me) vs. "new math", I checked with my 8th grade honor student.  He has been taught -5^2 = -5 * -5 = 25. 

I hope he hasn't been taught that.

Why?

Because I would prefer math teachers to teach math correctly.

Up until a few hours ago, that's exactly what I would have said.

But that doesn't mean you were taught that -5^2 was 25. Lots of times we do things differently that we were taught. It could be for any number of reasons: we remember incorrectly, it's easier to do incorrectly, simple error, etc. Or maybe we were absent that day. Or maybe we just don't care.

 

[Serenity Now]

Honestly, I'm just stunned that -5^2 suddenly isn't what it was when I was in school.

Oh, but it is.

No. It's not. I was taught that -5*-5 = 25. I get all the rigamarole about the parentheses, etc. But I was taught to look at -5 squared as -5*-5. And so I did.What's worse is I'm going to be preparing to take the Praxis II for elementary content in the spring and now I wonder how much other math isn't what it was when I was 12.

 

[Chase Stuart]

I haven't read the entire thread, but it seems that the mathematicians have determined the answer to be -25, which is contrary to what I thought. After reading the first few pages of "old math" (me) vs. "new math", I checked with my 8th grade honor student. He has been taught -5^2 = -5 * -5 = 25.

I hope he hasn't been taught that.

Why?

Because I would prefer math teachers to teach math correctly.

Up until a few hours ago, that's exactly what I would have said.

But that doesn't mean you were taught that -5^2 was 25. Lots of times we do things differently that we were taught. It could be for any number of reasons: we remember incorrectly, it's easier to do incorrectly, simple error, etc. Or maybe we were absent that day. Or maybe we just don't care.

Are you implying that my teachers were right and I am wrong? You are lucky you're a protected member, or your warning level would be going up.Anyway, I was taught that -5^2 was 25. Are we positive the default rule (with no parentheses) is -5 is not its own integer, but the "-" is an add-on? Or however Smoo worded it.

 

[Aussie Cowboy]

I haven't read the entire thread, but it seems that the mathematicians have determined the answer to be -25, which is contrary to what I thought. After reading the first few pages of "old math" (me) vs. "new math", I checked with my 8th grade honor student. He has been taught -5^2 = -5 * -5 = 25.

I hope he hasn't been taught that.

Why? Up until a few hours ago, that's exactly what I would have said. That's how I was tought.

I'm only 18 so I can't relate to you guys saying that -5^2 use to equal 25 but all through grade school, high school, and now college I have seen many problems like that involving no paranthesises and I think its always been pretty basic for everyone.

I'm 22. We were never tought anything other than -5^2 is (-5)^2. It's said "negative five squared." I'm not sure why this is so surprising either way though; it's just the presumption we were tought; where you place the parenthesis tells you the correct way of doing it. The debate on the default rule might be interesting, but isn't very useful.

:smoo:

 

[Chase Stuart]

I haven't read the entire thread, but it seems that the mathematicians have determined the answer to be -25, which is contrary to what I thought. After reading the first few pages of "old math" (me) vs. "new math", I checked with my 8th grade honor student. He has been taught -5^2 = -5 * -5 = 25.

I hope he hasn't been taught that.

Why? Up until a few hours ago, that's exactly what I would have said. That's how I was tought.

I'm only 18 so I can't relate to you guys saying that -5^2 use to equal 25 but all through grade school, high school, and now college I have seen many problems like that involving no paranthesises and I think its always been pretty basic for everyone.

I'm 22. We were never tought anything other than -5^2 is (-5)^2. It's said "negative five squared." I'm not sure why this is so surprising either way though; it's just the presumption we were tought; where you place the parenthesis tells you the correct way of doing it. The debate on the default rule might be interesting, but isn't very useful.

:smoo:

Here's my excuse: my brain is currently fried and I've been doing nothing but studying for the last two weeks.

 

[Swapster]

OK, so now I'm convinced due to the order of operations that -5^2 should be -25. However, I fear that most if not all computer programs ever written and interpreted on current processors is doing it wrong.

To force the processor to intrepret it correctly would mean changing every formula that includes exponentiation to check for a negative base number and if found change the formula from something like x^2 to (-1*(x)^2). Otherwise, it comes out positive every time.

I think this could be a new Y2K for us programmers.

Will one of you alert the news media? I'll be getting my business cards ready. Swapster, Negative Exponentiation Specialist.

 

[Clayton Gray]

Honestly, I'm just stunned that -5^2 suddenly isn't what it was when I was in school.

Oh, but it is.

No. It's not. I was taught that -5*-5 = 25. I get all the rigamarole about the parentheses, etc. But I was taught to look at -5 squared as -5*-5. And so I did.What's worse is I'm going to be preparing to take the Praxis II for elementary content in the spring and now I wonder how much other math isn't what it was when I was 12.

Bummer. GL

 

[Keys Myaths]

OK, so now I'm convinced due to the order of operations that -5^2 should be -25. However, I fear that most if not all computer programs ever written and interpreted on current processors is doing it wrong.

To force the processor to intrepret it correctly would mean changing every formula that includes exponentiation to check for a negative base number and if found change the formula from something like x^2 to (-1*(x)^2). Otherwise, it comes out positive every time.

I think this could be a new Y2K for us programmers.

Will one of you alert the news media? I'll be getting my business cards ready. Swapster, Negative Exponentiation Specialist.

I guarantee you the news media doesn't care.

 

[Swapster]

OK, so now I'm convinced due to the order of operations that -5^2 should be -25.  However, I fear that most if not all computer programs ever written and interpreted on current processors is doing it wrong.

To force the processor to intrepret it correctly would mean changing every formula that includes exponentiation to check for a negative base number and if found change the formula from something like x^2 to (-1*(x)^2).  Otherwise, it comes out positive every time.

I think this could be a new Y2K for us programmers. 

Will one of you alert the news media?  I'll be getting my business cards ready.  Swapster, Negative Exponentiation Specialist.

I guarantee you the news media doesn't care.

What about Nerds Weekly?

 

[Clayton Gray]

I haven't read the entire thread, but it seems that the mathematicians have determined the answer to be -25, which is contrary to what I thought.  After reading the first few pages of "old math" (me) vs. "new math", I checked with my 8th grade honor student.  He has been taught -5^2 = -5 * -5 = 25. 

I hope he hasn't been taught that.

Why?

Because I would prefer math teachers to teach math correctly.

Up until a few hours ago, that's exactly what I would have said.

But that doesn't mean you were taught that -5^2 was 25. Lots of times we do things differently that we were taught. It could be for any number of reasons: we remember incorrectly, it's easier to do incorrectly, simple error, etc. Or maybe we were absent that day. Or maybe we just don't care.

Are you implying that my teachers were right and I am wrong? You are lucky you're a protected member, or your warning level would be going up.Anyway, I was taught that -5^2 was 25. Are we positive the default rule (with no parentheses) is -5 is not its own integer, but the "-" is an add-on? Or however Smoo worded it.

Actually, I'm going out on a limb and saying that on that day, you listened for half a minute then said, "This #### is so easy" before looking around to check out the hottie next to you in her cheerleading uniform.

 

[rolyaTy]

OK, so now I'm convinced due to the order of operations that -5^2 should be -25. However, I fear that most if not all computer programs ever written and interpreted on current processors is doing it wrong.

To force the processor to intrepret it correctly would mean changing every formula that includes exponentiation to check for a negative base number and if found change the formula from something like x^2 to (-1*(x)^2). Otherwise, it comes out positive every time.

I think this could be a new Y2K for us programmers.

Will one of you alert the news media? I'll be getting my business cards ready. Swapster, Negative Exponentiation Specialist.

No, just like with google, calculators and excel, one must understand how to use them before expecting them to churn out correct answers. If you were to use parentheses like you're supposed to, the computers do fine with them. Even without parenthesis, the computers do the calculations correctly...it's just that we think we're telling the computer to do one thing, when we're really telling it something else.

 

[thatguy]

Honestly, I'm just stunned that -5^2 suddenly isn't what it was when I was in school.

Oh, but it is.

No. It's not. I was taught that -5*-5 = 25. I get all the rigamarole about the parentheses, etc. But I was taught to look at -5 squared as -5*-5. And so I did.What's worse is I'm going to be preparing to take the Praxis II for elementary content in the spring and now I wonder how much other math isn't what it was when I was 12.

I would guess that pretty much all of it's changed. Yeah, see, mathematicians are constantly updating their formulas and equations and stuff. Get away from it for even a few years, and it's like walking around in the dark. Most textbooks are updated at least yearly, so if you study, make sure you have an updated textbook. Especially algebra--mathematicians are now thinking that algebra might not even exist.... I know, I know, I was shocked too.

 

[Keys Myaths]

OK, so now I'm convinced due to the order of operations that -5^2 should be -25. However, I fear that most if not all computer programs ever written and interpreted on current processors is doing it wrong.

To force the processor to intrepret it correctly would mean changing every formula that includes exponentiation to check for a negative base number and if found change the formula from something like x^2 to (-1*(x)^2). Otherwise, it comes out positive every time.

I think this could be a new Y2K for us programmers.

Will one of you alert the news media? I'll be getting my business cards ready. Swapster, Negative Exponentiation Specialist.

I guarantee you the news media doesn't care.

What about Nerds Weekly?

Maybe...heh.

 

[Clayton Gray]

I haven't read the entire thread, but it seems that the mathematicians have determined the answer to be -25, which is contrary to what I thought.  After reading the first few pages of "old math" (me) vs. "new math", I checked with my 8th grade honor student.  He has been taught -5^2 = -5 * -5 = 25. 

I hope he hasn't been taught that.

Why? Up until a few hours ago, that's exactly what I would have said. That's how I was tought.

I'm only 18 so I can't relate to you guys saying that -5^2 use to equal 25 but all through grade school, high school, and now college I have seen many problems like that involving no paranthesises and I think its always been pretty basic for everyone.

I'm 22. We were never tought anything other than -5^2 is (-5)^2. It's said "negative five squared." I'm not sure why this is so surprising either way though; it's just the presumption we were tought; where you place the parenthesis tells you the correct way of doing it. The debate on the default rule might be interesting, but isn't very useful.

:smoo:

I thought I was the only one that cought that.

 

[rolyaTy]

I haven't read the entire thread, but it seems that the mathematicians have determined the answer to be -25, which is contrary to what I thought.  After reading the first few pages of "old math" (me) vs. "new math", I checked with my 8th grade honor student.  He has been taught -5^2 = -5 * -5 = 25. 

I hope he hasn't been taught that.

Why? Up until a few hours ago, that's exactly what I would have said. That's how I was tought.

I'm only 18 so I can't relate to you guys saying that -5^2 use to equal 25 but all through grade school, high school, and now college I have seen many problems like that involving no paranthesises and I think its always been pretty basic for everyone.

I'm 22. We were never tought anything other than -5^2 is (-5)^2. It's said "negative five squared." I'm not sure why this is so surprising either way though; it's just the presumption we were tought; where you place the parenthesis tells you the correct way of doing it. The debate on the default rule might be interesting, but isn't very useful.

:smoo:

I thought I was the only one that cought that.

Looks like you thaught wrong.

 

[Serenity Now]

I only wish algebra didn't exist. That stuff sucks. It's all geometry. Give me a theorem and I'm good to go. Crap, they probably canned those too. Math education is fascinating to me, I have to say. My fifth grader is learning to do stuff I wasn't even shown til I was in high school, and I was in the smart kid classes. Gizmos like lattice calculation for multiplication is nifty too.

 

[Swapster]

OK, so now I'm convinced due to the order of operations that -5^2 should be -25.  However, I fear that most if not all computer programs ever written and interpreted on current processors is doing it wrong.

To force the processor to intrepret it correctly would mean changing every formula that includes exponentiation to check for a negative base number and if found change the formula from something like x^2 to (-1*(x)^2).  Otherwise, it comes out positive every time.

I think this could be a new Y2K for us programmers. 

Will one of you alert the news media?  I'll be getting my business cards ready.  Swapster, Negative Exponentiation Specialist.

No, just like with google, calculators and excel, one must understand how to use them before expecting them to churn out correct answers. If you were to use parentheses like you're supposed to, the computers do fine with them. Even without parenthesis, the computers do the calculations correctly...it's just that we think we're telling the computer to do one thing, when we're really telling it something else.

So, how would you put the original equation in code? Assuming intNumber is the variable to be taken to the 2nd power, I would code it as (intNumber^2). If intNumber is set to -5, the processor calculates this as 25 not -25. Same if you make it (intNumber)^2.

 

[Clayton Gray]

OK, so now I'm convinced due to the order of operations that -5^2 should be -25. However, I fear that most if not all computer programs ever written and interpreted on current processors is doing it wrong.

To force the processor to intrepret it correctly would mean changing every formula that includes exponentiation to check for a negative base number and if found change the formula from something like x^2 to (-1*(x)^2). Otherwise, it comes out positive every time.

I think this could be a new Y2K for us programmers.

Will one of you alert the news media? I'll be getting my business cards ready. Swapster, Negative Exponentiation Specialist.

I'm not sure why Google botches it, but Excel and non-graphing calculators are taking whatever is in that cell or on the screen and squaring it. That is the same thing as putting parenthesis around the number.Any graphing calculator (where you type the entire -5^2 before hitting enter) will offer -25.

 

[rolyaTy]

OK, so now I'm convinced due to the order of operations that -5^2 should be -25.  However, I fear that most if not all computer programs ever written and interpreted on current processors is doing it wrong.

To force the processor to intrepret it correctly would mean changing every formula that includes exponentiation to check for a negative base number and if found change the formula from something like x^2 to (-1*(x)^2).  Otherwise, it comes out positive every time.

I think this could be a new Y2K for us programmers. 

Will one of you alert the news media?  I'll be getting my business cards ready.  Swapster, Negative Exponentiation Specialist.

No, just like with google, calculators and excel, one must understand how to use them before expecting them to churn out correct answers. If you were to use parentheses like you're supposed to, the computers do fine with them. Even without parenthesis, the computers do the calculations correctly...it's just that we think we're telling the computer to do one thing, when we're really telling it something else.

So, how would you put the original equation in code? Assuming intNumber is the variable to be taken to the 2nd power, I would code it as (intNumber^2). If intNumber is set to -5, the processor comes calculates this as 25 not -25. Same if you make it (intNumber)^2.

I would make a specific operator for negative values separate from a minus sign, like most calculators do. If someone uses the operator representing a sign...then it'd be -5, if they use the operator representing subtraction, it'd be -(5).

 

[Juxtatarot]

Anyone who believes the original answer is 7 is an integerist.Integerists believe all integers were not created equal. They believe positive integers are superior to negative ones. They believe a negative integer must exist in (parentheses) to be its true self. Shame on you, integerists!!!! I am for the liberation of integers all along the dark half of the number line. The negative ones should be allowed to break free from their (parentheses) and live a life distinctly separate from their opposites.THIS OPPRESSION SHOULD NOT BE TOLERATED. WHO IS WITH ME??

 

[HarryManback]

Google says...

http://www.google.com/search?q=-5%5E2&sour...:en-USfficial

 

[NCCommish]

Anyone who believes the original answer is 7 is an integerist.

Integerists believe all integers were not created equal. They believe positive integers are superior to negative ones. They believe a negative integer must exist in (parentheses) to be its true self. Shame on you, integerists!!!!

I am for the liberation of integers all along the dark half of the number line. The negative ones should be allowed to break free from their (parentheses) and live a life distinctly separate from their opposites.

THIS OPRESSION SHOULD NOT BE TOLERATED. WHO IS WITH ME??

Sorry to be the one to break it to you but Smoo is already leading the charge for the liberation of the negative numbers.

 

[Swapster]

OK, so now I'm convinced due to the order of operations that -5^2 should be -25.  However, I fear that most if not all computer programs ever written and interpreted on current processors is doing it wrong.

To force the processor to intrepret it correctly would mean changing every formula that includes exponentiation to check for a negative base number and if found change the formula from something like x^2 to (-1*(x)^2).  Otherwise, it comes out positive every time.

I think this could be a new Y2K for us programmers. 

Will one of you alert the news media?  I'll be getting my business cards ready.  Swapster, Negative Exponentiation Specialist.

No, just like with google, calculators and excel, one must understand how to use them before expecting them to churn out correct answers. If you were to use parentheses like you're supposed to, the computers do fine with them. Even without parenthesis, the computers do the calculations correctly...it's just that we think we're telling the computer to do one thing, when we're really telling it something else.

So, how would you put the original equation in code? Assuming intNumber is the variable to be taken to the 2nd power, I would code it as (intNumber^2). If intNumber is set to -5, the processor comes calculates this as 25 not -25. Same if you make it (intNumber)^2.

I would make a specific operator for negative values separate from a minus sign, like most calculators do. If someone uses the operator representing a sign...then it'd be -5, if they use the operator representing subtraction, it'd be -(5).

Programs don't work that way.I'm just saying... that any business apps that include exponentiation that could possibly be given a negative number are going to calculate incorrectly, based on what I have learned here.

To force them to calculate correctly would take a lot of programming changes, looking for a negative being fed into the equation (not by a human operator but from elsewhere in the program - it could be a result of a previous calculation done on numbers from a database, for instance).

 

[rolyaTy]

It'd be something like:NumVal = xNumSign=y %either a -1 or a 1Num=x*ysolution=Num^2

 

[Swapster]

It'd be something like:

NumVal = x

NumSign=y %either a -1 or a 1

Num=x*y

solution=Num^2

Solution would still be wrong.NumVal = 5

NumSign = -1

Num = 5 * -1

Num = -5

Solution = -5^2, interpreted by computer as 25.

 

[Juxtatarot]

Anyone who believes the original answer is 7 is an integerist.

Integerists believe all integers were not created equal.  They believe positive integers are superior to negative ones.  They believe a negative integer must exist in (parentheses) to be its true self.  Shame on you, integerists!!!! 

I am for the liberation of integers all along the dark half of the number line.  The negative ones should be allowed to break free from their (parentheses) and live a life distinctly separate from their opposites.

THIS OPRESSION SHOULD NOT BE TOLERATED.  WHO IS WITH ME??

Sorry to be the one to break it to you but Smoo is already leading the charge for the liberation of the negative numbers.

Clearly one man cannot lead this on his own. Even the mighty Smoo.

 

[NCCommish]

Anyone who believes the original answer is 7 is an integerist.

Integerists believe all integers were not created equal.  They believe positive integers are superior to negative ones.  They believe a negative integer must exist in (parentheses) to be its true self.  Shame on you, integerists!!!! 

I am for the liberation of integers all along the dark half of the number line.  The negative ones should be allowed to break free from their (parentheses) and live a life distinctly separate from their opposites.

THIS OPRESSION SHOULD NOT BE TOLERATED.   WHO IS WITH ME??

Sorry to be the one to break it to you but Smoo is already leading the charge for the liberation of the negative numbers.

Clearly one man cannot lead this on his own. Even the mighty Smoo.

Blasphemer

 

[Maurile Tremblay]

To force the processor to intrepret it correctly would mean changing every formula that includes exponentiation to check for a negative base number and if found change the formula from something like x^2 to (-1*(x)^2). Otherwise, it comes out positive every time.

No, a negative base number should come out positive when it is squared. But in the expression -5^2, the base number (i.e., the number that gets squared) isn't negative. It's five.