Slicing Three-Dimensional Figures and Identifying the Resulting Cross-Sections

Learning Resource Type

Learning Activity

Subject Area

Mathematics
Digital Literacy and Computer Science

Grade(s)

7

Overview

In this activity, students will use the Interactivate Cross Section Flyer Tool to discover the cross-sections that result from slicing three-dimensional figures. Students will use a graphic organizer to collect data on prisms, pyramids, and cylinders.

Cross-Section Graphic Organizer

Phase

During/Explore/Explain
Digital Literacy and Computer Science (2018) Grade(s): 7

DLCS18.7.23

Demonstrate the use of a variety of digital devices individually and collaboratively to collect, analyze, and present information for content-related problems.

UP:DLCS18.7.23

Knowledge

Students know:
  • that often there exists a devices that will be better for a task than another device.

Skills

Students are able to:
  • use multiple devices to research and collect data to compile a presentation.

Understanding

Students understand that:
  • in research, the tool used is less important than the information gathered.
Mathematics (2019) Grade(s): 7

MA19.7.19

Describe the two-dimensional figures created by slicing three-dimensional figures into plane sections.

UP:MA19.7.19

Vocabulary

  • Two-dimensional figures
  • Three-dimensional solids
  • plane sections

Knowledge

Students know:
  • the difference between a two-dimensional and three-dimensional figure.
  • The names and properties of two-dimensional shapes.
  • The names and properties of three-dimensional solids.

Skills

Students are able to:
  • Discover two-dimensional shapes from slicing three-dimensional figures. For example, students might slice a clay rectangular prism from different perspectives to see what two-dimensional shapes occur from each slice.

Understanding

Students understand that:
  • slicing he prism from different planes may provide a different two-dimensional shape.
  • There are specific two-dimensional shapes resulting from slicing a three-dimensional figure.
Mathematics (2019) Grade(s): 7 - Grade 7 Accelerated

MA19.7A.35

Describe the two-dimensional figures created by slicing three-dimensional figures into plane sections. [Grade 7, 19]

UP:MA19.7A.35

Vocabulary

  • Two-dimensional figures
  • Three-dimensional solids
  • plane sections

Knowledge

Students know:
  • the difference between a two-dimensional and three-dimensional figure.
  • The names and properties of two-dimensional shapes.
  • The names and properties of three-dimensional solids.

Skills

Students are able to:
  • discover two-dimensional shapes from slicing three-dimensional figures. For example, students might slice a clay rectangular prism from different perspectives to see what two-dimensional shapes occur from each slice.

Understanding

Students understand that:
  • slices the prism from different planes may provide a different two-dimensional shape.
  • There are specific two-dimensional shapes result from slicing a three-dimensional figure.

Learning Objectives

Students will name, draw, and describe cross-sections that result from slicing three-dimensional figures.

Students will demonstrate the use of a digital tool to analyze cross-sections of three-deminsional figures.

Activity Details

Prior to completing this activity, ensure the students have an understanding of the difference between vertical and horizontal slicing of three-dimensional figures. Students also need to understand when a slice is made through a three-dimensional figure, the result is a two-dimensional figure called a cross-section. One effective way to illustrate these concepts is through the use of play-dough three-dimensional models. Demonstrate both horizontal and vertical slices with string so the students visually see the resulting two-dimensional cross-sections. Have students turn and talk about the resulting cross-section and then share their observations with the class.

Pass out the graphic organizer for students to complete using the Interactivate Cross Section Flyer digital tool. Students can complete the activity in groups of 3-4 or independently.

Assessment Strategies

Exit Ticket: Display a three-dimensional figure that was not used within the lesson and have the students name the cross-sections resulting from vertical and horizontal slices. (Example: cone) 

The teacher will observe students as they use the digital tool.

Variation Tips

If there is not technology available, the activity can be modified by allowing the students to complete the graphic organizer independently using play-dough models.

Background / Preparation

Create play-dough models of three-dimensional figures prior to the lesson.  

Visit the website Interactivate Cross-Section Flyer to become familiar with manipulating the figures.

Students will need access to the Interactivate Cross-Section Flyer Website.

Copies of the graphic organizer for students to complete either individually or in groups.

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