Square the scale factor when working with scaled drawings and area. The 19th lesson in a series of 22 introduces calculating actual areas from scale drawings. The lesson encourages pupils to use the square of the scale factor to find the area. Scholars first find the area of the scale drawing and multiply it by the square of the scale to find the actual area.

Concepts

area, scale drawings, scale, scale factors, constant of proportionality, proportional reasoning, proportions

Show More Show Less

Additional Tags

math

Show More Show Less

Instructional Ideas

• Lead a discussion on why pupils should square the scale factor by using area calculations
• Using the apartment scale drawing, compare the area of the different rooms

Classroom Considerations

• Each pair needs rulers

Pros

• The answer keys for the in-class work show the computations needed to arrive at the solution
• Scaffolding provides hints for struggling pupils

Cons

• None

Common Core

7.G.A.1 MP2