# Lesson 10

Complete Equations

### Lesson Purpose

The purpose of this lesson is for students to represent numbers 11–19 with equations.

### Lesson Narrative

In previous lessons students composed and decomposed numbers 11–19 with 10 ones and some more ones. They saw numbers 11–19 represented with written numbers, phrases such as “10 and 2,” expressions, and equations. In this lesson, students interpret equations and fill in the missing numbers to complete equations for numbers 11–19 (MP2).

- Action and Expression

- MLR8

### Learning Goals

Teacher Facing

- Represent numbers 11–19 with equations.

### Student Facing

- Let’s write equations to show numbers 11–19.

### Required Materials

Materials to Gather

### Required Preparation

Activity 3:

- Gather materials from:
- Make or Break Apart Numbers, Stages 1 and 2
- Bingo, Stages 1-4
- Number Race, Stages 1 and 2
- Grab and Count, Stage 1
- Tower Build, Stages 1 and 2

### Lesson Timeline

Warm-up | 10 min |

Activity 1 | 10 min |

Activity 2 | 10 min |

Activity 3 | 20 min |

Lesson Synthesis | 10 min |

Cool-down | 0 min |

### Teacher Reflection Questions

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