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 9: Subtract Tenths or Hundredths
Required Preparation
Materials to Gather
Number cubes
Materials to Copy
Blackline Masters
Target Numbers Stage 9 Recording Sheet

Narrative
Students subtract hundredths and tenths to get as close to 1 as possible. Students start their first equation with 2 and take turns rolling a number cube and choosing whether to subtract that number of hundredths or tenths and write an equation. The difference becomes the first number in the next equation. The player who gets closest to 1 in 6 rounds, without going below 1, is the winner.
Additional Information
Each group of 2 needs one number cube.


aligns: no