Skitch & Popplet app smashing subtraction

We have been working on subtraction in math. We have been using lots of pictures, manipulatives, and equations to solve these simple subtraction problems.   Since our addition Popplet had gone so well, I thought we might try creating a subtraction Popplet.

We began our activity in the Skitch app. Skitch is a free app that allows you to take a photo and then write on it. I've seen this app used a lot for labeling things, but I thought it would be perfect for showing subtraction because it would allow us to mark out the number of items we were subtracting.

I had my students select a number and get that many blocks. Then they took a picture of
their blocks in the skitch app. The students used the tools in the skitch app to mark out blocks to represent a subtraction equation.  I had them show all the ways to subtract from that number with their pictures. The students saved each picture to their camera roll.  Then the students imported their pictures in the Popplet app and wrote the corresponding subtraction equations.   Here are a couple of the finished products.