I created this one for Chey, more than the other two. She has been working on addition for a while now, and I want to re-enforce the education. I also made this one expandable, I made it with subtraction, multiplication, and division as well.
Simple. All you need is popsicle sticks, a marker, and clothes pins.
Draw the signs on the popsicle sticks at the third marks.
Write the numbers on the clothes pins. I did 0-9 and just use two on the double digit numbers.
This is how it will work when using it.
All of them fit in to a gallon bag just perfectly.