# Lesson 17

Multiply Decimals and Whole Numbers

### Lesson Purpose

The purpose of this lesson is for students to multiply a whole number by any amount of tenths or hundredths.

### Lesson Narrative

In previous lessons students made sense of decimals to the thousandth and added and subtracted decimals to the hundredth. The goal of this lesson is for students to multiply decimals to the hundredth in a way that makes sense to them. They apply their work with decimal place value and multiplication of whole numbers. Students may draw pictures (hundredths grids or tape diagrams) or reason using place value or properties of operations (distributive and associative). As with addition and subtraction of decimals, students see that for multiplication, they can use what they know about whole number multiplication as long as they pay close attention to place value.
• Action and Expression

### Learning Goals

Teacher Facing

• Multiply a whole number by tenths and hundredths in a way that makes sense to them.

### Student Facing

• Let’s multiply whole numbers by tenths and hundredths.

### Required Materials

Materials to Copy

• Small Grids

Building Towards

### 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

If you were to teach this lesson again what would you do the same? What would you change?