Explain how the scale factor is calculated and how the numerical value of the scale factor differs for enlargements and reductions.

For this case, what you should keep in mind is that you have three cases to calculate the scale factor.

Dimensions of a figure:

L = k * l

Where,

L: side of a figure applying scale factor.

l: original side of a figure.

Area of a figure:

A: k ^ 2 * a

Where,

A: Area of a figure applying scale factor.

a: Original area of a figure.

Volume of a figure:

V = k ^ 3 * v

Where,

V: Volume of a figure by applying scale factor.

v: Original volume of a figure.

For reductions of a figure:

k <1

To enlarge a figure:

k> 1