Please Note: In the video the answer to 5/8 as a percent is 67.5%. This is incorrect.
The correct answer is 62.5%.

A percent is a ratio (fraction) whose denominator is 100.

To convert a fraction to percent form, form a proportion by setting the fraction equal to $\frac{P}{100}$ and solve for P.

Example:

Write 5/8 in percent form.

Solution: Set the fraction equal to P/100 and solve for P: $\frac{5}{8} = \frac{P}{100}$

Solve by setting cross products equal to each other.

$5 \cdot 100 = 8 \cdot P$

500 = 8P

Divide by 8:

P = $\frac{500}{8}$= 62.5

5/8 = 62.5%

To convert from percent form to fraction form:

Drop the percent sign and place the value over 100. Then simplify the fraction.

Example:

Write 55% in fraction form.

Solution:

55% = $\frac{55}{100}$

Reduce the fraction:

$\frac{55}{100} = \frac{11}{20}$