18 months andamp up. Increase children's confidence with counting and number recognition using these nature-inspired Magnetic Wood Cookie Counters. Made in part using Poly+, this set is durable enough for both indoor and outdoor numeracy activities. Each piece has a black magnetic backing that enables convenient use on blackboards or whiteboards. Set includes pieces marked with numbers 0 through 20. Each piece measures 2" in diameter x .5"H.