Physical Materials

• Paper
• Pen or Pencil

Instructions:

1. Use mental math to solve 57 + 24.
2. After you have done the calculations in your head, jot down your strategy on paper. Consider trying out more than one way of solving this expression.
3. When you are ready, watch the videos below to hear how others thought about this problem. Consider how the methods take advantage of the base ten structure of our number system.

If you are taking the course for credit, submit your work below.