Lesson 9
Measure Figures Made From Prisms
Lesson Purpose
The purpose of this lesson is for students to find the volume of figures composed of two nonoverlapping right rectangular prisms by adding the volumes of the nonoverlapping parts.
Lesson Narrative
In the previous lesson, the figures students worked with showed the unit cubes, providing the opportunity to visualize the number of unit cubes and find volume in a variety of ways. In this lesson, the figures composed of two nonoverlapping right rectangular prisms do not show the individual cubes. This encourages students to apply the volume formulas and make connections between expressions and the way the figures can be decomposed. Given an expression and a solid figure composed of two rectangular prisms, students determine how to decompose the figure to match the given expression (MP2, MP7).
 Representation
 MLR7
Learning Goals
Teacher Facing
 Find the volume of a figure composed of rectangular prisms in which unit cubes are not shown.
Student Facing
 Let’s find the volume of more figures.
Required Materials
Materials to Copy
 Isometric Dot Paper Standard
Required Preparation
CCSS Standards
Lesson Timeline
Warmup  10 min 
Activity 1  20 min 
Activity 2  15 min 
Lesson Synthesis  10 min 
Cooldown  5 min 
Teacher Reflection Questions
What connections did students make between the different strategies shared? What questions did you ask to help make the connections more visible?
Suggested Centers
 Five in a Row: Multiplication (3–5), Stage 4: Three Factors (Addressing)
 Rolling for Fractions (3–5), Stage 1: Equivalent Fractions (Supporting)
Print Formatted Materials
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Additional Resources
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