# Lesson 8

Meters and Kilometers

### Lesson Purpose

The purpose of this lesson is for students to describe the multiplicative relationship between kilometers and meters and express the former in terms of the latter.

### Lesson Narrative

Previously, students learned that 1 meter is 100 times as long as 1 centimeter. They converted measurements in meters to centimeters. In this lesson, they extend their understanding of metric units of length to include kilometers.

Students develop a sense for 1,000 meters by reasoning multiplicatively about shorter measurements in meters. For example, they see that 1,000 meters is 20 times the length of a 50-meter pool, 10 times the length of a 100-meter track, and so on. In doing so, students develop an awareness of 1 kilometer as 1,000 times as long as 1 meter.

Students use tables and what they know about multiples of 1,000 to support their reasoning as they multiply whole numbers by 1,000 to convert kilometers to meters (MP7).

• Action and Expression
• MLR7

Activity 1: How Long is One Kilometer?

### Learning Goals

Teacher Facing

• Describe the multiplicative relationship between kilometers and meters.
• Express kilometers in terms of meters.

### Student Facing

• Let’s explore measurements in meters and kilometers.

### Required Materials

Materials to Gather

Materials to Copy

• How Long is One Kilometer?

Building On

### 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

What part of the lesson went really well in terms of helping students reason about the size of 1 kilometer and its relationship to 1 meter? What part of the task supported this reasoning?

### Suggested Centers

• How Close? (1–5), Stage 6: Multiply to 3,000 (Addressing)
• Compare (1–5), Stage 3: Multiply within 100 (Supporting)