A scale in mathematics refers to the ratio of a drawing in comparison to the size of the real object. A ratio is a relative size that represents typically two values. For example, 1:3 pears and grapefruits represents that there is one pear for every three grapefruit.
In using scale, the ratio represents sizes of actual drawings or models. If the scale is 1:10, then the model or drawing is 10 times smaller than the actual object. If a die-cast car is listed as a 1:10 or 1/10 diecast, then the actual car is 10 times larger than the model car.
Scale is often used to represent items like diecast cars, maps and other items. A real horse may be 1,500 mm high, but the drawing of the horse may be 150 mm high. As with the diecast car, this scale is represented by writing the ratio 1:10.
Using scale drawings can also help with representing buildings. Architects often use scale when drawing a design, or to build models to show the design to others. A doll house is a good example of something that can be represented in scale. If a doll house modeled after a real house is 50 times smaller, then that scale can be represented by writing the ratio 1:50.