Calculations involving percentages of quantities. Working with increases and decreases as well as expressing a quantity as a percentage of another quantity.
Part ofMathsNumeracy
Some percentages can be converted easily into fractions and worked out more quickly that way. For example:
\(50\% = \frac{{50}}{{100}} = \frac{1}{2}\)
\(25\%=\frac{25}{100}=\frac{1}{4}\)
\(75\%=\frac{75}{100}=\frac{3}{4}\)
\(20\%=\frac{1}{5}\)
Now try the example questions below.
Find \(50\%\) of \(\pounds400\).
\(50\% \,of\,\pounds400\)
\(= \frac{1}{2} \times 400\)
\(= \pounds200\)
\(20\%\) of the \(225\) pupils in S4 at a particular school catch the school bus home.
How many pupils catch the school bus?
\(20\% = \frac{{20}}{{100}} = \frac{1}{5}\)
So \(20\%~of~225\)
\(= 45\).
\(45\) pupils catch the school bus.
