standard_description: Mentally add 10 or 100 to a given number 100–900, and mentally subtract 10 or 100 from a given number 100–900.
problem_activity: Stage 2: Three-digit Numbers
Required Preparation
Materials to Gather
Number cards 0–10
Materials to Copy
Blackline Masters
Mystery Number Stage 2 Directions

Narrative
Students pick three cards and make a mystery three-digit number. Students give clues based on the sentence starters.


aligns: no