Modeling - Hard Multiplication
Trixie was 3 years
and 9 months at the time that this video was made.
The Problem
I have 2 parts of the snake. You have 3 times as many parts as
I have. How many parts do you have?
What To Look For In This Video
- I started to build the model myself. I represented the parts of the snake that I have.
- I suppose that I might have waited to see what Trixie would do with this question, but I was pretty sure that she did not understand it at all. So I asked her if she understood. When she said "no" I explained.
- I showed Trixie what "just as many," "2 times as many," and "3 times as many" mean.
- Having built the model for Trixie, I asked how many parts of the snake she has. She counted 3 - the 3 groups of 2 - not the 6 individual "parts of the snake." She doesn't know what to count. (But notice that she did know what to count when she had 2 times as many parts. Her understanding is unstable - sometimes she gets it, and sometimes she doesn't.
- I don't know what Trixie was thinking when she counted only 4 of her rocks. And after that, she lost the ability to focus on the problem. So I stopped trying to explain.