Building upon the multi-faceted early childhood development benefits of unit block play, each solid beech truck in the Block Science Big Truck series is designed to overlay a lesson on how a simple machine works. This large wooden cement truck carries a cement mixer which is connected to the wheels of the truck by 5 different gears. When the truck is moved, the cement mixer turns, teaching children to recognize and investigate the mechanics of using gears. Unit Blocks and these accompanying Block Science Big Trucks teach simple machine and STEM concepts while encouraging construction, deconstruction, teamwork, social interaction and self-expression. Dimensions: 5.5"L x 15.25"W x 9"H (14 x 38.7 x 22.8 cm cm). Suggested Age: 3+