That’s What You Mean When You Say “Think”!

That’s a quote from a student.  My wife likes the story and thought I should post it.  It’s from when I taught at Southern Illinois University back in the eighties.

First, you need a little background.

I would tell calculus students that there is a special method for solving many math problems.  When they asked what it was, I toldthem that  it was called “horse sense” (or “common sense”) – that is “think”.

When they would ask me about a homework problem I would say, “Well, let’s think about it.”  I also told them to read the examples to see how the author thought about the problem and did it – not just as a “model”

A calculus student came to ask me about a problem.  He was not an outstanding student but I’m sure he worked hard; he was serious and very pleasant.  He showed me the problem he was trying to do.   He said he had looked at all the examples but he couldn’t make the problem fit any of them.  He keep showing me how each one was different than the homework problem.  (Each was similar, though; each using the same basic idea.)

I asked him if he undestood how they did the examples, which I was sure he did.  He said yes.  I said,  “then, just look at the problem”.  He said he had but that it didn’t exactly fit the examples.  I repeated, “Just look at the problem.”  He did for about one minute and said, “Oh”.  He then proceeded to do it correctly and then was able to explain to me the idea behind each example.

The student then got excited and said,

That’s what you mean when you say “Think”!