Calculate the simplification number and the numerator.

First, calculate the simplification number by dividing the two denominators.

Second, calculate the numerator by dividing it by the simplification number.

If you would like to have a vivid explanation with a detailed example, please read the page Simplifying/Reducing Fractions - Learn this magic trick!

**Step 1: Calculate the Simplification Number**

To calculate the *simplification number*, divide the denominator of the first fraction (81) by the denominator of the simplified fraction (9):

Simplification Number = 81 ÷ 9 = 9

**Step 2: Calculate the numerator**

To calculate the *numerator* of the simplified fraction, divide the numerator of the first fraction (63) by the simplification number (9):

Numerator = 63 ÷ 9 = 7