This inviting set of 20 double-sided stones is ideal for counting, pattern making, number bonds and sorting activities. These durable two-color counters, made from a unique stone mix, can be used both indoors and outside, and in water and sand. They are ideal for use alongside the 10-Frame Tray, which supports additional activities such as sequencing and an understanding of number bonds to 10. Contains 20 stones measuring 1.75 inches across.