Lesson 23
Divide Whole Numbers by Decimals
Lesson Purpose
Lesson Narrative
In the previous lesson, students divided whole numbers by one tenth and one hundredth and made generalizations about how to divide any whole number by those units. The purpose of this lesson is for students to extend that work to divide whole numbers by any number of tenths or hundredths (with total value less than 1). Consistent divisors are used in repetition to highlight relationships between the dividends and the quotients (MP8). Students evaluate expressions with larger divisors such as \(12 \div 0.2\) in order to encourage them to use the relationship between multiplication and division. Rather than drawing 12 unit squares and dividing all of them into groups of 2 tenths, students may draw a single whole divided into 2 tenths and then use multiplication.
 Action and Expression
Learning Goals
Teacher Facing
 Divide whole numbers by decimals to the hundredths using strategies based on place value.
Student Facing
 Let’s divide whole numbers by decimals.
Required Materials
Materials to Copy
 Small Grids
Required Preparation
Lesson Timeline
Warmup  10 min 
Activity 1  15 min 
Activity 2  20 min 
Lesson Synthesis  10 min 
Cooldown  5 min 
Teacher Reflection Questions
Suggested Centers
 Compare (1–5), Stage 4: Divide within 100 (Supporting)
 Compare (1–5), Stage 6: Add and Subtract Fractions (Supporting)
Print Formatted Materials
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Additional Resources
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