Question

Express $7\mathrm{cm}8\mathrm{mm}$ as $\mathrm{cm}$ using decimals.

Answer 1

Express$7\mathrm{cm}8\mathrm{mm}$ as$\mathrm{cm}$ using decimals.

We know that,

$\begin{array}{rcl}1\mathrm{mm}& =& \frac{1}{10}\mathrm{cm}\\ 7\mathrm{cm}8\mathrm{mm}& =& \left(7+\frac{8}{10}\right)\mathrm{cm}\\ & =& \left(7+0.8\right)\mathrm{cm}\\ & =& 7.8\mathrm{cm}\\ \therefore 7\mathrm{cm}8\mathrm{mm}& =& 7.8cm\end{array}$

$\therefore$The decimal of$7\mathrm{cm}8\mathrm{mm}$ as $\mathrm{cm}$ is$7.8\mathrm{cm}$