Purpose: To explain Scale Drawings to others.
Scale drawings are basically any depiction of a real structure based as a model or "drawing". We use these all the times with maps, figurines, etc. To use scale drawings you must first have a hypothetical scenario where you'd need to do so. Let's say you have a drawing of a door, with a scale of 2in.=3ft (meaning that 2 inches of the drawing portrayed is equivalent to 3 feet of the actual door), and the width of the actual door is 72 inches (1 ft.=12in.). The objective is to find the width of the drawing, this can be simplified to: 72 inches= 6ft, 6ft= 4in.(because of the "scale factor" which states that 2 inches on the paper is equivalent to 3ft of the actual door). We now know that the width of the drawing is 4 inches!
More examples could be:
1. A model ship is built to a scale 1cm: 4m. The length of the model is 40 cm. What is the length of the actual ship? For this one it's quite simple, really. The length of the model is only 40 cm, 1cm translates to 4m, so you would multiply 4mx40cm which would give the size of the real ship. The answer for this one is 160.
2. If 1 inch represents 75 miles on a map, then how many inches will represent 1500 miles?
Well, for this one: 1in.=75 mi. so you should take 1500/75 to get your answer. This is because dividing 1500 by the inch conversion of 75 will give you the number of inches the map represents.
3. On a map the distance from Srpingfield to Pleasantville is 6 in. The map scale is 1/2 in. = 20 mi. Find the actual distance between Springfield and Pleasantville. With 6 in. and the scale being 1/2 in., that means there are 12 "1/2's", so multiplying 20x12=240. So the answer is 240 miles.
The following photo is used for reference to scales, and I took it from here.
