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. Details: 3 assorted shapes and designs 7.09" x 4.33" packaging size 2" approximate maximum size Set of 15 sensory stones Durable for outdoor and indoor use Safe for use in mud, water and sand Made of stone For ages 2 and up