Sunday 4 April 2010

An Afternoon With Mike - Part 3

There was also some math, which really hasn't changed much either. By this point though, I have moved over to share his sofa with him and have been helping him with fractions.
Me: Ok, so to divide a fraction you multiply the inverse.
Mike: I don't get it.
The Screen: 4/5 ÷ 3
Me: Well, write it down.
He pulls out his notebook and writes it down.
Me: And 3, as a whole number, is the same as 3/1. Write it down.
He does.
Me: So to divide a fraction you multiply the inverse.
Mike: I don't get it.
Even as he is saying this he is writing the correct equation of 4/5 x 1/3, so he obviously gets it.
Me: Yes like that, so to divide a fraction you multiply by its inverse.
Mike: Yeah, I don't get it.
He totally got it. He did the multiplication in the notebook in 2 seconds, getting 4/15. Which was one of the multiple choice answers on the screen. He clicked it and got the answer correct.
Me: See? To divide a fraction you just multiply the inverse.
Mike: I still don't get it. Why? How does that work?
Me: WHAT?!? I DON'T KNOW WHY!! I JUST KNOW HOW TO DO IT - TO DIVIDE A FRACTION YOU MULTIPLY ITS INVERSE! I DON'T KNOW HOW IT WORKS, JUST, TO DIVIDE A FRACTION YOU MULTIPLY ITS INVERSE!! -- YOU DON'T NEED TO KNOW WHY!!!
Yes, I should not be a teacher.

2 comments:

Unknown said...

hahaha!

Although we talked about that in our math class - it is VERY hard to explain why it works. You would have to demonstrate with visual pieces of something.

Erin said...

I like math with pies.... But only the part where you get to eat the pie. I can sympathize with your brother in that I cannot understand the simplest math problems. I'm guessing he's probably a little better at it than I am though.