Interlocking Gram Unit Cubes - 1,000 Pieces

I grabbed these for teaching area and perimeter, and the fact that each cube has three interlocking sides makes building solid rectangular prisms so much easier. They click together securely but still come apart without a struggle.

My third graders finally understand volume because they can physically stack these cubes and count them. The interlocking sides click together securely but come apart easily for quick clean-up.

I was pleasantly surprised by how sturdy the cubes feel when snapped together; the three interlocking sides hold really well. My only small gripe is that the container they came in isn't the most durable for storing all 1,000 pieces. Still, they've been perfect for teaching my son about volume and m