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Question

Dear Mitch,

I was at the beach and I heard some older kids reading some math problems they were supposed to do over the summer and one of the questions I thought was really weird because it sounded so easy but then wasn't.  They read At the store there were 5 apples, and you take away 3, how many do you have left?

I thought that was easy:  You have 2 left.

But they said the answer was 3.  They even had the answer from the teacher and they were supposed to figure out why 3 was the right answer.  How could it be 3?

Thanks,

Pete 

Answer

Dear Pete,

Believe it or not, the question you heard is an old and famous one, and I think I heard it for the first time when I was a child!

And you DID hear correctly -- the answer is 3!

This question is used to see how closely you are paying attention to the words of the math problem, because it's very important when solving proboems like this to try to understand the exact facts of the situation instead of just rushing to apply whatever math you already know -- even if that math doesn't really solve what needs to be solved.

If the question had asked this:  "If you go to the store and they have 5 apples, and you take away 3, how many would they have left -- " . . .  Well, then, yes, you would be correct in saying 2.   BUT, I know the question, and it doesn't ask how many you have LEFT, but how many you HAVE. . .  So, now... think about it all over again:  

You go to the store, the store has five apples. . . You take away 3 . . .  How many do YOU HAVE?

YOU have whatever you "take away" from the store, NOT what you LEAVE THERE!

See the difference between "How many do YOU have"? and "How many would be left over"? 

Or even "How many would you have LEFT"? 

Anyway, it's great to hear that you're thinking about math in the middle of the summer, especially because I like to know that I'm not the only one! 

I hope this helps,

Mitch