A scale factor essentially takes all of the lengths on an object and multiplies them by itself.
For instance, a square with side lengths of 4 scaled by a factor of 2 would have scaled side lengths of 4 x 2 = 8, and that same square scaled by a factor of 1/2 would have side lengths 4 x 1/2 = 2. Scaling something by a factor of 1 keeps it exactly the same, since any number multiplied by 1 is unchanged - this means that 1 is basically the "pivot number" for scaling.
Any scale factor greater than one will scale an object up to larger dimensions, while any scale factor less than one will scale an object down to smaller dimensions.
