The purpose of this activity is for students to learn Stage 2 of the Number Puzzles center. Students work together to use number cards to make addition and subtraction equations within 20 true. Each digit (0–9) can only be used once in a puzzle. Puzzles with fewer than 10 spaces will have leftover cards.

• Display Puzzle 1.
• “Which equation would you start with? Why would you start there?”

The purpose of this activity is for students to choose from activities that focus on adding and subtracting within 20. Students choose from any of previously introduced stages of the listed centers.

• Number Puzzles
• Shake and Spill
• Compare

• “What method do you use most often to add within 20? Why do you use that method the most?”