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# Fractions

### Multiplication of fractions

• To multiply to fractions, multiply the numerators and the denominators.
• Common factors can be cancelled either during the multiplication or at the end to give answer in simplest form.
• To multiply mixed numbers, convert them to improper fractions first.

For example:

\begin{eqnarray*} \frac{7}{8} \times \frac{16}{21} &=& \frac{7 \times 16}{8\times 21} \\
&=& \frac{\cancelto{1}{7} \times \cancelto{2}{16}}{\cancelto{1}{8}\times \cancelto{3}{21}} \\
&=& \frac{1 \times 2}{1 \times 3} \\
&=& \frac{2}{3}
\end{eqnarray*}