Adding and Subtracting in Space

Use Questions 11–13 in the Solving Problems with Sums and Differences section of the Student Guide to summarize the lesson. These problems involve estimating both sums and differences. Ask student pairs to solve the problems.

In Question 12 it is important to consider whether numbers should be rounded up or down.

Have several students share their answers and explain their reasoning with the class.

Use Math Practices Expectations 1 and 5 on the Math Practices page in the Student Guide Reference section to guide the discussion as students share their solutions to Questions 11–13.

Assign the Addition and Subtraction Quiz Assessment Master from the Teacher Guide. This quiz focuses on the key concepts developed in the first six lessons of the unit. Before students begin the quiz, direct their attention to Questions 7 and 8. Review Math Practices Expectations 1 and 5 on the Math Practices page in the Student Guide Reference section to help students remember to read the problems carefully and show how they solved the problem.