standard_description: Given a two-digit number, mentally find 10 more or 10 less than the number, without having to count; explain the reasoning used.
problem_activity: Stage 1: Grade K Shapes
Required Preparation
Materials to Gather
Counters
Materials to Copy
Blackline Masters
Which One Stage 1 Gameboard

Narrative
One partner chooses a shape on the gameboard. The other partner asks questions to figure out what shape they chose. Students may use counters to cover up shapes that have been eliminated. Students work with simple shapes such as circles, rectangles, and triangles.


aligns: no