Here's a little puzzle I wrote. The math is pretty straightforward on this one but the wording of the question, though unambiguous, goes beyond many high school students' "word problem translating" skills.

Here goes:

If the difference between two numbers is 20, what is the difference between their product and the product of two other numbers whose difference is 26 and whose sum is the same as the sum of the first two numbers?

## Simple math word puzzle

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### Simple math word puzzle

There's no such thing as a funny sig.

### Re: Simple math word puzzle

I get 138.

**Spoiler:**

pollywog wrote:I want to learn this smile, perfect it, and then go around smiling at lesbians and freaking them out.Wikihow wrote:* Smile a lot! Give a gay girl a knowing "Hey, I'm a lesbian too!" smile.

### Re: Simple math word puzzle

ConMan wrote:I get 138.Spoiler:

**Spoiler:**

There's no such thing as a funny sig.

### Re: Simple math word puzzle

Here's my method:

**Spoiler:**

### Re: Simple math word puzzle

My experimental data tell me that the answer is

http://dtai.cs.kuleuven.be/krr/idp-ide/ ... 070ff7ceae

**Spoiler:**

http://dtai.cs.kuleuven.be/krr/idp-ide/ ... 070ff7ceae

Last edited by ingdas on Mon May 04, 2015 1:07 pm UTC, edited 1 time in total.

### Re: Simple math word puzzle

Yat wrote:Here's my method:Spoiler:

Nicely done. That's my method also, but the high school students I've given it to (the ones who get the answer at all) follow ConMan's method and use four variables. Much longer and more fiddly that way.

There's no such thing as a funny sig.

### Re: Simple math word puzzle

Wildcard wrote:Nicely done. That's my method also, but the high school students I've given it to (the ones who get the answer at all) follow ConMan's method and use four variables. Much longer and more fiddly that way.

That is probably because they usually see word problem of that type when they are learning systems of equations.

### Re: Simple math word puzzle

Yat, you're not using fewer variables, you're just doing some of it in your head/from memory. I would prefer from any student to see the full solution.

**Spoiler:**

### Re: Simple math word puzzle

Wildcard wrote:ConMan wrote:I get 138.Spoiler:~~I think~~your algebra is off....Spoiler:

Oh yeah. Stupid factor of two.

pollywog wrote:I want to learn this smile, perfect it, and then go around smiling at lesbians and freaking them out.Wikihow wrote:* Smile a lot! Give a gay girl a knowing "Hey, I'm a lesbian too!" smile.

### Re: Simple math word puzzle

That was not my intent. I actually used one additional variable: the mean.SPACKlick wrote:Yat, you're not using fewer variables, you're just doing some of it in your head/from memory.

Well, I've not been a student for decades, but thanks. Now I adapt my explanations to the audience, and considering I was in the puzzles section of a webcomic forum, I think it was detailed enough.SPACKlick wrote: I would prefer from any student to see the full solution.Spoiler:

Now, about "the full solution", this is just another method, and you couldn't really put it differently because it is just a series of operations. Of course my method could have been presented in a detailed, "classroom - proof" way, it would still illustrate the ability to look at the problem before getting head down into the bruteforce calculations. I'm not a teacher but I know this was the kind of things I was rewarded for when I was a student, and this is the kind of shortcuts that makes the problem a puzzle and not only an exercise.

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