This appealing set of 15 counting stones displays irregular number arrays from 1 to 5, using three different patterns of indented circles to represent each number. The tactile nature of the stones means they are perfect for sensory math investigations and can be used outdoors, including in water, sand and mud. The stones will help children with counting, number recognition, learning that numbers can be represented in a range of ways, subitizing, and number bonds. Contains 15 stones in three shades, measuring approximately 2". Safe for age 2+. Recommended age 2-6 years