Lesson 19

The purpose of this lesson is for students to find the number that makes 10 when added to a given number.

Students have access to tools used throughout the year, including two-color counters, connecting cubes, fingers, 10-frames, and bead tools, to help them find the number that makes 10. With repeated experience, students may know some of the numbers needed to make 10 by memory, such as 5 and 5 or 9 and 1. Students fill in equations to represent these compositions and decompositions of 10. This lesson is optional because the standards do not require students to fill in equations with one missing addend in kindergarten.

If students need additional support with the concepts in this lesson, refer back to Unit 5, Section C in the curriculum materials.

• Students can use their bead tool from a previous lesson.

• Students can use their bead tool from a previous lesson.

• Gather materials from:
  • Shake and Spill
  • Number Race
  • Grab and Count
  • What's Behind My Back?
  • Pattern Blocks

What opportunities are you giving students to reflect on their understanding of the mathematical content?