Little architects and engineers will learn through play as they build with ECR4Kids Wooden Hollow Block Set. These oversized unit-style hollow blocks introduce shape recognition and early math concepts like doubling comparison and symmetry. Students employ problem-solving and critical thinking skills as they stack and build with increasing complexity. Open-ended play supports imagination and creativity and helps develop independence as children design ramps racetracks and towers in countless arrangements. Use individually or pair up for teamwork collaboration and cooperative learning. Constructed from sustainably harvested birch plywood with a durable finish sealing the wood surface and resisting scratching. A UV inhibitor helps furniture resist ultraviolet light and yellowing. Natural birch plywood is extremely durable and will hold up to everyday use in daycares and preschools great for the home. Hollow blocks are lightweight and easy to grasp for two-handed movement. This set of 18 hollow blocks includes two flat boards one half-wide ramp one ramp six quarter units two half-wide units two units and four square units.