## Teaching algebraic expressions: Counting smileys

January 29, 2011 1 Comment

I love this task for introducing the concept of variable and algebraic expressions through problem solving. It combines numerical, geometric, and algebraic thinking. The figure below shows the standard version of the task. Of course some easier versions would ask for the 5th figure, then perhaps 10th figure, then the 100th figure, and then finally for the nth figure. This actually depends on the mathematical maturity of the students.

An alternative version which I strongly encourage that teachers should try is to simply show first the diagrams only (see below) with the following instruction: Read more of this post