Question

Express as $\mathrm{cm}$ using decimals:

$9\mathrm{cm}8\mathrm{mm}$.

Answer 1

Step 1: Convert the unit from millimetre to centimetre

Given data: $9\mathrm{cm}8\mathrm{mm}$.

It is known that, $1\mathrm{mm}=\frac{1}{10}\mathrm{cm}=0.1\mathrm{cm}$.

Thus, $8\mathrm{mm}=\left(8\times 0.1\right)\mathrm{cm}=0.8\mathrm{cm}$.

Step 2: Add the same units to get final length

$$\begin{gathered} 9\mathrm{cm}8\mathrm{mm} \\ =9\mathrm{cm}+0.8\mathrm{cm} \\ =9.8\mathrm{cm} \end{gathered}$$

Therefore, the given length can be expressed in centimetre as $\mathbf{9}\mathbf{.}\mathbf{8}\mathbf{}\mathbf{cm}$.