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: Numbers to 99 by 1
Required Preparation
Materials to Gather
Dry erase markers
Sheet protectors
Materials to Copy
Blackline Masters
Write the Number Stage 1 Gameboard

Narrative
Students count by 1 and choose whether to count forward or backward. Gameboards go from 39–60, 69–90, and 78–99.


aligns: no