Whole and Part Workshop

It all started with the ubiquitous “is this right?” from many different students.  With that we began a series of mini-classes to teach children how to check their subtraction answers by using addition.  We also decided to use this opportunity to try and help children understand the relationship between the “whole and the parts”.  We began with subtraction problems and identified the whole and the part we were taking away. We used circles cut in two parts to help provide a visual.  After arriving at a subtrahend, we had children add the two parts back together to see if they returned them to the original “whole”.  Once children could do that we began to try and help them see the general statements that can be made, entering the world of algebra.

We began to refer to W-P=P, P+P=W, and the hardest W-?=P.  The last was tricky because you really had to understand that you can arrive at any part by subtracting the other.