Duct Tape + Cars = Math

I had no clue what else to name this post, so bare with me!  I could have named it something really long like, How to Find the Missing Number using Duct Tape and Cars-- but I spared you the boring and long title for something short, sweet, and to the point : )

I shared our Christmas Tree addition activity with you a couple weeks ago, and to practice math facts once more we brought out some cars.  Some days Tyler knows his facts and other days it is quite an emotional experience, so I am not sure if we should keep drilling or move on in our Math U See book... any opinions?  

Anyways...

Using duct tape, I made a triangle on the floor and then drew out triangles with the numbers to create and solve the equation.  In the upside down triangle, one angle is blank and the other angle contains a number to help solve the equation.  The angle pointing down contains the sum. 

All the cars begin at the bottom of the upside down triangle.  

In the picture below, we started off with 9 cars (the sume).  Tyler drove 6 cars to one corner to figure out the problem: ___ + 6 = 9, thus 3 cars were left and so it was our answer.

 

By moving x number of cars to one side of the triangle, he was able to see that the missing number was the number of cars left at the bottom of the triangle.

Do you have any car fans?!  This would be fun to do to learn about shapes, too!