Simply Magic Complete Base Ten Starter Set, designed to help children ages 6+ develop number sense. It is a math manipulative, often used in elementary education to teach place value and basic arithmetic operations. The set includes 131 pieces: 100 units (ones) 20 rods (tens) 10 flats (hundreds) 1 cube (thousands) These blocks are sturdy, durable, and designed for visual and hands-on learning. The blocks are made of plastic.