standard_description: Understand subtraction as an unknown-addend problem. For example, subtract 10 – 8 by finding the number that makes 10 when added to 8.
problem_activity: Stage 3: Describe and Find
Required Preparation
Materials to Gather
Geoblocks
Solid shapes

Narrative
Students describe solid shapes so their partner can identify the shape out of a set of 4–6 solid shapes.


aligns: no