Modeling - Hard Subtraction 2
Trixie was 3 years
and 4 months old at the time that this video was made.
The Problem
You have 4 chickens. You have 3 more chickens than I have.
How many chickens do I have?
What To Look For In This Video
- Trixie seems tired. (This is the third problem in a row for her and I may have pushed her a little too far for one sitting.)
- Trixie correctly gets started by counting out 4 chickens for herself.
- I always try to understand what logic leads children to their answers. My experience is that children who have been taught well rarely make random guesses. But in this case I have no idea on what basis Trixie decided initially that I have 5 chickens.
- But any guess at all is a good start. At least now we have 2 sets of objects (her chickens and my chickens) and we can discuss who has more, and how much more.
- It seems very clear that as far as Trixie is concerned, the question "how many more than me do you have?" means exactly the same thing as the question "how many do you have?"
- It is interesting to compare Trixie's work on this Hard Subtraction 2 problem with her work on Easy Subtraction and her work on Hard Subtraction 1. All 3 of these problems were presented to her in one sitting.