2 Scale FactorThe relationship between measurements on the drawings can be described by using a scale factor.When you make a drawing twice as wide and twice as tall, your scale drawing has a scale factor of 2:1.1/2 inch on the original =1 inch on the scale drawing.
3 measurement on model : measurement on actual or original Scale FactorSo, the scale factor is always written asmeasurement on model : measurement on actual or originalOrOriginal: Each square = ½ inch Drawing: Each square = 1 inchScale Factor: 2:1 or 2/1
4 Simplifying the Scale Factor Original: Drawing:Each square= 1/2 inch Each square = 1/4 inchWhat is the scale factor on the smaller scale drawing of Calvin?
5 Scale Factor Scale factors are usually expressed using 1 unit. Real Eiffel Tower:324 meters tallLEGO Eiffel Tower: meters tall.Instead of writing1.08 : 324,we write1 : 300or 1/300
6 Common Scale FactorsHouse Plans/Floor Plans: ¼” scale, which means 1/4 inch stands for 1 foot: 1:48.N scale model trains: 1:148.Hot Wheels: 1:64Radio-controlled car: 1:10Traditional Dollhouses: 1:12, 1:18, or 1:24Barbie Dollhouse: 1:6
8 Scale Models and Drawings are Proportional The reason a scale model or scale drawing looks similar to the actual or original thing is that all measurements on the model/drawing are proportional to measurements on the actual/original.This means that every part of the drawing is the same number of times bigger or smaller than the original or real thing.Stewie’s foot on the original drawing is ½ inch long.How long is Stewie’s foot on a 2:1 drawing?On a 0.5:1 drawing?If you made a 10:1 scale drawing of the original Stewie, how long would his foot be?
9 ScaleAnother way to relate models to actual things is to use a scale, which includes units in different measurements.
10 Use a Proportion to Solve Scale Drawing/Model problems.