Computing Actual Lengths from a Scale Drawing - 7.1 - Lesson 18

Computing Actual Lengths from a Scale Drawing - 7.1 - Lesson 18

Author: Todd Parks

Student Outcomes

  • Given a scale drawing, students compute the lengths in the actual picture using the scale.
  • Students identify the scale factor in order to make intuitive comparisons of size then devise a strategy for efficiently finding actual lengths using the scale.
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What and How

In this lesson we are going to take scale drawings and find out what the actual size is of the object that is pictured.

REMEMBER:  A reduction has a scale factor less than 1 and an enlargement has a scale factor greater than 1.

Our scale factor is our constant.

Below I am going to show you how to use an xy table as well as tape models to help you figure out the actual length and width of the scale drawings.

IXL - J.13 Scale Drawings and Scale Factors


This is the IXL 7th grade target J.13 Scale Drawings and Scale Factors. Perfect practice for Lessons 17, 18, and 19 of the 7th grade common core.

Blank Printable Copy of Lesson 18

We were able to finish the first three questions on Day 1 of this lesson.

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