standard_description: Prove polynomial identities and use them to describe numerical relationships. For example, the polynomial identity (x^(2) + y^(2))^(2) = (x^(2 )– y^(2))^(2) + (2xy)^(2 )can be used to generate Pythagorean triples.
problem_activity: Stage 4: Subtract within 20
Required Preparation
Materials to Gather
Colored pencils or crayons
Number cards 0–10
Paper clips
Materials to Copy
Blackline Masters
Capture Squares Stage 4 Gameboard
Capture Squares Stage 4 Spinner

Narrative
Students spin to get a number (16–20) and flip a card (0–10). They subtract the number on the card from the number on the spinner. The spinner includes a wild space where students can choose their own number.


aligns: no