Lesson 3

The purpose of this lesson is for students to add and subtract 10 from multiples of 10.

In this lesson, students build on their understanding of tens as they add 10 to and subtract 10 from multiples of 10. Students learn that they can think of adding or subtracting 10 as adding or subtracting a ten from a number of other tens. In the first activity, students use towers of 10 to physically add or subtract a ten from a multiple of 10. In the second activity, students learn a new stage of the Five in a Row center, where they choose a card with a multiple of 10 and decide whether to add or subtract 10 in order to cover five spaces in a row on their gameboard. They may choose to continue to use towers of 10 if helpful.

• Create a set of cards from the blackline master for each group of 2.

• Gather materials from previous centers: 
  • Five in a Row, Stages 1–4
  • How Close, Stages 1 and 2
  • Number Puzzles, Stages 1 and 2

Reflect on times you observed students listening to one another’s ideas today in class. What norms would help each student better attend to their classmates’ ideas in future lessons?