Print the math sheets in color, or use the b/w masters to copy front to back on green paper. There are 20 problems on each mattress sheet and ten on each “pea”. Cut the peas and fold down the triangles. As children open the triangle, the flap tells them to either add or subtract the two numbers beneath. This is good for attending to detail and changing function easily. You can laminate and have them use Vis-à-vis pens, or they can work in partners etc. This product is great as a center, whole group (with document camera) or for small group.