# Scale Drawings By Barb Leach 7 th Grade Mathematics Owensville Middle School.

## Presentation on theme: "Scale Drawings By Barb Leach 7 th Grade Mathematics Owensville Middle School."— Presentation transcript:

Scale Drawings By Barb Leach 7 th Grade Mathematics Owensville Middle School

Scale Drawings MA, NO, 3, E, 07 Solve problems involving proportions, such as scaling and finding equivalent ratios

Career Areas Mapmakers use scales as they determine the size a map will be. Craftspeople who construct models of ships, automobiles, or other objects need to determine a scale to create an authentic reproduction of the desired size.

Vocabulary Scale: the ratio of the distance on a map to the actual distance Example: 1 cm = 100 miles Scale Drawing: a drawing that is similar but either larger or smaller than the actual object, for example, a road map or a building blueprint.

Example Architects draw buildings to scale in blueprints. A room in a new home will be 4.6 meters long and 3.3 meters wide. If the scale of the blueprint is 1 cm = 2.5 m, what should the dimensions be in the scale drawing. LengthWidth Scale1 cm = l cmscale1 cm = w cm Actual2.5cm 4.6 mactual2.5cm = 3.3 m 2.5 x l = 1 x 4.6 2.5 x w = 1 x 3.3 2.5 2.5 2.5 2.5 l = 1.84 w = 1.32 The drawing length is 1.84 cm. The drawing width is 1.32 cm.

Practice Write and solve a proportion to find scale and actual distances.

Assessment Glencoe Math P. 334 do 1-8 Additional practice activity sheets

Resources/References Glencoe Mathematics Applications and Connections Course 2 copyright 2001 Scott Foresman-Addison Wesley Middle School Math Course 2 copyright 2002 Mailbox magazine reproducibles