# Lesson 9

Expressions and Equations

### Lesson Purpose

The purpose of this lesson is for students to make sense of expressions and equations that represent numbers 11–19.

### Lesson Narrative

Students connect their understanding of numbers 11–19 as ten ones and some more ones to expressions (10 + _____.) Then, they match equations to 10-frame representations of teen numbers.

- Engagement

- MLR8

### Learning Goals

Teacher Facing

- Make sense of expressions and equations that represent numbers 11–19.

### Student Facing

- Let’s show numbers 11–19 in different ways.

### Required Materials

Materials to Gather

Materials to Copy

- Make or Break Apart Numbers Stage 2 Recording Sheet
- Make or Break Apart Numbers Stage 2 Number Mat 11-19
- Numbers and Expressions Cards
- Make or Break Apart Numbers Stage 2 Gameboards

### Required Preparation

Activity 1:

- Create a set of cards from the blackline master for each group of 4.

Activity 3:

Gather materials from:

- Bingo, Stages 1-4
- Number Race, Stages 1 and 2
- Grab and Count, Stage 1
- Tower Build, Stages 1 and 2

### CCSS Standards

Addressing

### Lesson Timeline

Warm-up | 10 min |

Activity 1 | 15 min |

Activity 2 | 10 min |

Activity 3 | 20 min |

Lesson Synthesis | 5 min |

Cool-down | 0 min |

### Teacher Reflection Questions

As students worked in their small groups today, whose ideas were heard, valued, and accepted? How can you adjust the group structure tomorrow to ensure each student’s ideas are a part of the collective learning?