Lesson 6

The purpose of this lesson is for students to make sense of Put Together/Take Apart, Both Addends Unknown story problems.

In a previous section, students composed and decomposed numbers up to 9. In this lesson, students first act out a Put Together, Total Unknown story problem, which was introduced in the previous lesson. Then students are introduced to a questionless Put Together/Take Apart, Both Addends Unknown story problem. Red and yellow apples are used as a context so that students can easily represent the story problems with two-color counters (MP2). In the next lesson, students will solve a Put Together/Take Apart, Both Addends Unknown story problem. 

• Gather materials from: 
  • What's Behind My Back, Stage 1
  • 5-frames, Stages 1 and 2
  • Make or Break Apart Numbers, Stage 1

What connections did students make between the Put Together, Total Unknown story problem and the Put Together/Take Apart, Both Addends Unknown story problem? How did acting out, representing and solving the Put Together, Total Unknown story problem prepare students to make sense of the Put Together/Take Apart, Both Addends Unknown story problem?