# Lesson 3

Unlabeled Tick Marks

### Lesson Purpose

The purpose of this lesson is for students to represent numbers within 100 on number lines that do not label each tick mark.

### Lesson Narrative

In a previous lesson, students were introduced to the number line and represented the location of numbers with labeled tick marks and points up to 20.

In this lesson, students use multiples of 5 and 10 to locate numbers up to 100 on the number line. Students leverage their understanding of skip counting by 5 and 10 to locate numbers and build on their understanding of the number line as a representation that includes all numbers. In future lessons, students will estimate numbers on a number line without any tick marks by approximating the location of the number relative to the position of represented numbers.

- Action and Expression

- MLR2

### Learning Goals

Teacher Facing

- Represent a whole number on a number line and describe the point in terms of its length from 0.
- Use skip-counting patterns to locate numbers on a number line.

### Student Facing

- Let’s locate numbers on the number line.

### Required Preparation

### Lesson Timeline

Warm-up | 10 min |

Activity 1 | 15 min |

Activity 2 | 20 min |

Lesson Synthesis | 10 min |

Cool-down | 5 min |

### Teacher Reflection Questions

How effective were your questions in supporting students’ thinking about the structure of the number line today? What did students say or do that showed they were effective?

### Suggested Centers

- Five in a Row: Addition and Subtraction (1–2), Stage 6: Add within 100 with Composing (Supporting)
- How Close? (1–5), Stage 3: Add to 100 (Supporting)