The **difference** between two values divided by the **average** of the two values. Shown as a **percentage**.

**Difference** means to subtract one value from another (such as Alex sold 15 tickets, and Sam sold 25; the difference between 25 and 15 is: 25-15 = **10)**

**Average** is the value half-way between:

(first value + second value)/2

The average of 25 and 15 is: (25+15)/2 = 40/2 = 20

The **DIFFERENCE** as a percentage is:

Difference is 25-15 = **10**

Average is (25+15)/2 = **20**

10 as a percentage of 20 is:

(10/20) * 100 = 100/2 = **50%**