# Lesson 15

Equal Groups, Larger Numbers

### Lesson Purpose

The purpose of this lesson is for students to multiply within 100, where one factor is a teen number.

### Lesson Narrative

The work of this lesson connects to previous work because students have seen a variety of ways to represent and solve problems in which one of the factors is a teen number. In this lesson students use their choice of strategy and representation to solve these types of problems. Students participate in a gallery walk to highlight different ways that they solved problems with a synthesis that highlights the area diagram to represent one of the problems. Students’ attention is drawn to scaling of area diagrams during the warm-up. While it’s not important that student representations are exact, it is important that any area diagrams presented to students are to scale.

- Engagement

- MLR8

### Learning Goals

Teacher Facing

- Multiply within 100, where one factor is a teen number.

### Student Facing

- Let’s solve some problems with equal groups that have larger numbers.

### Required Materials

Materials to Gather

Materials to Copy

- Centimeter Grid Paper - Standard

### Required Preparation

### CCSS Standards

### Lesson Timeline

Warm-up | 10 min |

Activity 1 | 20 min |

Activity 2 | 15 min |

Lesson Synthesis | 10 min |

Cool-down | 5 min |

### Teacher Reflection Questions

### Suggested Centers

- Compare (1–5), Stage 3: Multiply within 100 (Addressing)
- How Close? (1–5), Stage 5: Multiply to 100 (Addressing)

### Print Formatted Materials

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Student Task Statements | docx | |

Lesson Cover Page | docx | |

Cool Down | Log In | |

Teacher Guide | Log In | |

Teacher Presentation Materials | docx | |

Blackline Masters | zip |