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# What is a percentage?

A percentage is one-hundredth of a number. It uses the symbol $\%$. A percentage is a fraction where the denominator is $\Tblue{100}$.

$\Tred{50}\% = \frac{\Tred{50}}{\Tblue{100}} = \frac{1}{2} = 0.5,\quad \Tred{40}\% = \frac{\Tred{40}}{\Tblue{100}} = \frac{2}{5} = 0.4.$

To express a number as a percentage, write it in decimal form and multiply it by $\Tblue{100}$.

$0\Torange{.43}2 = \Tblue{100}\times 0\Torange{.43}2\% = \Torange{43.}2\%,\quad \frac{2}{7} = 0\Torange{.28}6 = \Torange{28.}6\%$

Percentages are often used to represent a fraction of a quantity.

Half a cake is the same as $50\%$ of the cake.

$25\%$ of $247$ is $\Torange{25}\%\times 247 = 0\Torange{.25}\times 247 = 61.75$

$26$ is $14.6\%$ of $178$ because $\displaystyle \frac{26}{178} = 0\Torange{.14}6 = \Torange{14.}6\%.$