A lot of the time, it's not really the best idea to have things full size. A map would be useless if it was full size, a toy car dowsn't really want to be the same size as a normal car.
When we have this issue, we use a scale diagram or a scale model.
What is a scale diagram.
A scale diagram is just a diagram where everything has been reduced by the same factor, it could be half the size, a tenth of the size or anything else.
How are scales written?
Scales are written as a ratio such as 1: 100 or 1:50 000
What does this mean:?
Scales are read left to right. The scale 1:100 for example, would mean that every 1 unit of length on the scale is the same as 100 units in real life.
So something that was 2 cm long in real life would be 200cm long in real life.
Example 1: A model car is 1.5 cm tall. If the scale is 1:100, how tall would the car be in real life.
All we need to do here is multiply by the scale factor.
1.5 x 100 = 150 cm
Example 2: A model is made of a 2 m tall man. If the model is 4 cm tall, what is the scale?
The first thing we should notice here is that the units are different, so we need to make them the same.
2m = 200cm
Step 2 is to write these numbers as a ratio (remember the model comes first))
Out thirs and final step is to simplify this ratio.