Napier's Bones - Quickly teach Your Child Math With This Montessori Toy

Designed by John Napier in 1617, Napier's Bones is a fantastic way to explain and help your child understand how basic math functions. Consider the first "calculator" Napier's Bones is an invaluable to in any classroom environment. Whether you are a teacher in a traditional classroom or a parent homeschooling this is an essential ingredient to you curriculum. The frame measures 7.5" x 7.5" and the rods are cut from 1/8" thick alder wood. Two full sets of roads are included.