One of my newest math products is an equal/not equal sort. I started with just addition. I created a bunch of equal equations and not equal equations. Then I decided it was time to introduce my firsties to the fact that sometimes the equation can be written with the sum first (before the equal sign). So, I included some of these equations into my sorts. Then, I branched out and created one for subtraction equations and one in which there was a mix of addition and subtraction.
When my firsties tried this for the first time, I was amazed. It really seemed to split my class into two groups: the kids that have a full grasp of addition and subtraction and those that still were just not getting it. After quite a bit of practice, though, I am proud to say that this activity has really helped my kids to have a deeper understanding of these skills! I am so proud!