Modeling - Easy Subtraction

Rose was 5 years and 8 months at the time that this video was made.

The Problem

Suppose that you have 3 snakes and that someone gives you some more so that you now have a total of 7 snakes. How many snakes were you given?

(This problem is an example of Easy Subtraction. It can be represented by the equation 7 - 3 = . But it can also be represented by the equation 3 + = 7. Thought of in that way it is a problem in Algebra.)

What To Look For In This Video

Click here to see Eva solve a problem just like this one, but in a different way.
Click here. to download (in PDF format, in a new window) a detailed discussion of problems like Rose's and some thoughts on how to teach children to solve them.