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 6: Decimals
Required Preparation
Materials to Copy
Blackline Masters
Mystery Number Stage 6 Gameboard

Narrative
Students choose a mystery number (up to nine digits) from the gameboard. Students give clues using the given vocabulary.


aligns: no