Students apply their learning from the unit to flexibly use methods to subtract within 20. There is not one correct method to use, as it is based on each student’s understanding of the concepts of subtraction, their known facts, and the numbers in the problem. It is helpful for students to listen to and make sense of others’ reasoning about which method they used (MP3). In the first activity, students find differences in given expressions. In the second activity, students apply subtraction methods as they solve story problems with the unknown in all positions.

How did your students represent their work today? How might you support them in creating more efficient representations?