### 4.2.6 Percentages

This section is not completed yet, but in the meantime here are some practice questions.

Remember:
A percentage is like a fraction over $100$ and taking a percentage ‘of’ something means multiplying it by the fraction, e.g. $20\%$ of $15$ means \begin{align*} \frac{20}{100} \times 15 &= \frac{20\times15}{100}\\ &= \frac{300}{100}\\ &= 3 \end{align*}

Remember:
The quickest way to perform a percentage increase on a calculator is to multiply by $1$ plus the percentage as a decimal. E.g. to find $12$ increased by $5\%$, type $12\times1.05$ into your calculator.

Similarly, to decrease something by a percentage, multiply by $1$ minus the percentage as a decimal. E.g. to find $152$ decreased by $3\%$, type $152\times0.97$ into your calculator.