# Lesson 18

1 More or 1 Less with Towers and Numbers

### Lesson Purpose

The purpose of this lesson is for students to identify 1 more or 1 less than a given number.

### Lesson Narrative

Students use the cube towers from the previous lesson. They may notice that the tower and number just before the given number shows one less and the tower and number just after the given number shows one more. Students also discuss how to use the count sequence to identify one less and one more than a given number.

In the lesson synthesis, students practice saying the verbal count sequence to 20. Add variety to the counting by adding movement. For example, students can count as they clap, stomp their feet, or jump.

- Engagement

- MLR8

Warm-up: Act It Out: Forks for Dinner

### Learning Goals

Teacher Facing

- Identify one more and one less than a given number.

### Student Facing

- Let’s find 1 more or 1 less than a number.

### Required Materials

Materials to Gather

### Required Preparation

Activity 1:

- Each group of 2 needs cube towers of 1–10 and number cards 1-10.

Activity 3:

- Gather materials from:
- Math Stories, Stage 1
- Math Libs, Stage 1
- Number Race, Stage 1

### CCSS Standards

### Lesson Timeline

Warm-up | 10 min |

Activity 1 | 10 min |

Activity 2 | 15 min |

Activity 3 | 20 min |

Lesson Synthesis | 5 min |

Cool-down | 0 min |

### Teacher Reflection Questions

In future lessons, students will compare written numbers 1-10. How does the work with one more and one less help prepare students for this work?