Lesson 17

The purpose of this lesson is for students to practice adding and subtracting within 1,000.

This lesson is optional because it is an opportunity for extra practice that not all classes may need. In Activity 1, students learn stage 6 of the Target Numbers center. In this new stage, called Add Hundreds, Tens, or Ones, students add hundreds, tens, and ones to get as close to 1,000 as possible. In Activity 2, students learn Stage 7 of the Target Numbers center, called Subtract Hundreds, Tens, or Ones. Then, they choose to continue working on Target Numbers, or choose between two previously introduced centers focused on addition and subtraction within 1,000.

Each group of 2 needs 3 number cubes.

• Each group of 2 students needs 3 number cubes.
• Gather materials from:
  • Target Numbers, Stage 6
  • Five in a Row, Stages 7 and 8
  • How Close, Stage 4

Reflect on whose thinking was heard today. Reflect on whose thinking was not heard but could have enriched the conversations. What prompts or structures might better enable the latter to share their voices and reasoning?