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: Two-digit Numbers
Required Preparation
Materials to Gather
Dry erase markers
Number cards 0–10
Sheet protectors
Materials to Copy
Blackline Masters
Get Your Numbers in Order Stage 1 Gameboard

Narrative
Students remove the cards that show 10 before they start. Then they choose two number cards and make a two-digit number. Students write their number in any space on the board, as long as the numbers from left to right go from least to greatest. If students cannot place their number, they get a point. The player with the fewest points when the board is filled is the winner.


aligns: no