Solid Sorter

Choose a mode

Tap a solid to pick it up, then tap one of the bins to drop it in. Rolls = it has a curved surface; Doesn't roll = only flat faces. Tap a solid that's already sorted to move it again. When you're done, press Check. Reset returns every solid to the start.

3D math game · Best for grades 2-4

Solid Sorter

Solid Sorter presents a set of 3D shapes and asks one focused question: does this solid roll or stay flat? Sorting by the presence of a curved surface turns an abstract property into a physical decision students can reason about with confidence from grade 2.

What students practice

Classifying solids by surface type builds the foundational 3D shape vocabulary — flat face, curved surface, edge, vertex — that students extend in grades 3-4 to counting faces and distinguishing prisms from pyramids and cylinders from cones.

  1. Look at each 3D solid and decide whether it has any curved surface.
  2. Tap the solid to pick it up, then tap the correct bin: 'Rolls' for curved surfaces, 'Doesn't roll' for all-flat faces.
  3. You can move a solid to a different bin before pressing Check.
  4. Press Check when all solids are sorted.

How to use it at home or in class

A cylinder has two flat faces (the circular ends) and one curved surface (the side), so it rolls. A cube has six flat faces and no curved surface, so it stays put. The cylinder is the most common source of surprise, as students sometimes expect it to behave like a prism.

Students often try to sort by shape name ('ball', 'box') without examining the surfaces. The game forces surface inspection: only looking at whether any face curves predicts the roll outcome reliably.

Use it for individual practice, paired work, or a short class demonstration before worksheets.

Start with the game above, then continue with written practice to reinforce the skill.

Common questions

Which solids appear in the game?
Common primary-school solids: sphere, cylinder, cone, cube, rectangular prism, triangular prism, and pyramid — covering both curved and flat-only groups.
Which grades is this game for?
It fits grades 2-4, from first 3D shape recognition through the formal classification of solids by their properties.
How is this different from Net Folder, which also uses 3D solids?
Solid Sorter classifies finished shapes by a surface property (rolling). Net Folder is about how a flat net folds into a solid. Each game targets a distinct spatial concept.