Parallelogram Discovery

So during my sixth grade class today, we were attempting to discovery the area formula of a parallelogram from a rectangle.
I gave the students a piece of graph paper and a set of instructions.  They were to make a rectangle using whole number edges, find the area of their rectangle. Then they were going to draw a straight line from one corner to the opposite base, slide the piece over and form a parallelogram. With their parallelogram they were to then estimate the number of unit squares, state the base and state the height.
Then, they were going to compare the parallelograms to their rectangles.

It was going to be great! NOT!!!
First teacher mistake – I didn’t review what a rectangle looked like.
Second teacher mistake – I didn’t review what a parallelogram looked like.
Third teacher mistake – I got cocky thinking it was the best lesson in the world.

Luckily, my students were understanding and we stopped midway and reviewed what we were doing, talked about what the shapes looked like and overall I think it turned out well.

Hopefully, when we do it tomorrow with right triangles, it goes much better 🙂

I only wish I had taken pictures!!! 


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