Identify, name, and describe 3D shapes (sphere, cube, cone, cylinder) — flat vs. solid
Exercise Difficulty 2 ~2 min math.gK.f.gm.shapes_3d.ex_01

Solid Or Flat Sort

Prompt

Sort these 8 objects into two groups: FLAT (2D) and SOLID (3D). Tell me how you decided.

M-K-F-EX-29-A Photograph
Top-down photo of 8 objects on a wooden tray: paper-cut shapes (square, circle, triangle, rectangle — all on flat paper,

Top-down photo of 8 objects on a wooden tray: paper-cut shapes (square, circle, triangle, rectangle — all on flat paper, each ~3" in widest dimension) and 4 wooden geosolids (sphere ~2" diameter, cube ~2" edge, cone ~2" tall, cylinder ~2" tall). Two empty sorting trays labeled 'FLAT' and 'SOLID' below the objects.

How it's presented
mode manipulative manipulative 8 objects mix 2d and 3d with 2 sort trays
Answer criteria
type sorted set
expected
FLAT
['paper_square', 'paper_circle', 'paper_triangle', 'paper_rectangle']
SOLID
['sphere', 'cube', 'cone', 'cylinder']
Hints
  1. If you can pick it up and turn it, it's probably solid.
  2. If it's only paper-thin, it's flat (2D).
Misconceptions to watch
  • Confuses photo of cube with actual cube.
  • Says paper shape is solid because it can be picked up.
Used in lessons