# Lesson 3

### Lesson Purpose

The purpose of this lesson is for students to represent decimals to the thousandths place in expanded form.

### Lesson Narrative

The previous lesson introduced students to different ways of thinking about a decimal number, including by place value. The goal of this lesson is for students to make connections between familiar representations of decimals, such as grids or numerical form, and expanded form. Students have seen expanded form of whole numbers in a previous course and apply the same idea here to write expressions showing how many of each decimal place value is in a number. This sets students up for work in a future unit considering the relationship between place values.

### Learning Goals

Teacher Facing

• Relate different representations of the same number.
• Write decimals in expanded form.

### Student Facing

• Representemos milésimas.

### 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 unfinished learning or misunderstandings do your students have about the relationship between place values? How did you leverage those misconceptions in a positive way to further the understanding of the class?

### Suggested Centers

• Mystery Number (1–4), Stage 5: Six-digit Numbers (Supporting)
• Get Your Numbers in Order (1–5), Stage 4: Denominators 2, 3, 4, 5, 6, 8, 10, 12, or 100 (Supporting)