These cards can be used to help students create a visual using a 10-frame when using basic addition. They can play several different ways by simply matching them up or playing it like a memory game. Please check out the preview before purchasing. There are 4 different sets of cards, so it increases with difficulty. The cards are grouped by the outlining color, either green, blue, purple or orange. This makes it easy to accommodate different levels of students, as well as keep them sorted.