Math Activities with Stacking Cups!

I have some different toys in my house that I thought can be used for math practice and activities. I think that this Fisher Price Stacking set is SO cool!  They not only stack, but they click and turn into these neat balls (you can have 5 balls with 1-2, 3-4, 5-6, 7-8, 9-10 together or you can put 2-3, 4-5, 6-7, and 8-9 together).  They are a bit noisy if you roll them on hardwood and they aren't meant for throwing, but here are some math activities you can do with them...

• You can stack them on top of each other and make an addition or subtraction problem--you just need the cups and a paper.  I also made a short video to display what I mean.  Here is a link to my video.

•  You can put different problems that your students are working on inside of the balls (they are pictured on the outside just for display).  You can do pretty complicated problems too.

•  And who says you only have to put one in each ball?  

•  You can also have a race where you flash the card for the student and they have to pick the correct cup number (The cups are 1-10).

Can you think of any other ways to use these cups?