Math Mat Pond Life perfect for counting and sorting skills, Good for the Preschool Age and Kinders. There is one Sorting by size (small, medium, large) mat I print off four mats to use at one time. I use the with duck erasers and the turtle and frog counters from Lakeshore for the number counting mats. There are eight different math counting mats with numbers on them. Four of the math are self checking with matching black dots and the other four mats do not have the black dots for self checking. The kids love them and it's a super quick and easy math activity center.