Discover the scale factor by finding the constant of proportionality. Pupils investigate drawings to determine whether the distances are proportional. The activity defines the scale factor as the constant of proportionality, or unit rate, of proportional lengths. The class uses the information to find scale factors and lengths in the 17th section of a series of 22.

Concepts

unit rates, scale, scale drawings, scale factors, constant of proportionality, proportional reasoning, proportions

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Additional Tags

math

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Instructional Ideas

• Provide drawings that are not accurate scale drawings, and have the class explain why
• Create a museum walk of the scale drawings in the extension

Classroom Considerations

• The class should be comfortable with finding the constant of proportionality

Pros

• Helps guide instruction with scripted lesson plans
• Includes scaffolding suggestions to challenge the class

Cons

• None

Common Core

7.RP.A.2.b 7.G.A.1