Question

Express as centimetres using decimals: $9cm8mm$

Answer 1

Express the given unit in centimeters

As we know that, $1cm=10mm$

So, we can convert millimeters into centimeters by dividing it with $10$.

Given, $9cm8mm$

Here, we only need to convert $8mm$ into centimeters.

Using unitary method, we get,

$$\begin{gathered} \Rightarrow 10mm=1cm \\ \Rightarrow 1mm=\frac{1}{10}cm \\ \Rightarrow 8mm=\frac{8}{10}cm \\ \Rightarrow 8mm=0.8cm \end{gathered}$$

Thus, we can convert $9cm8mm$ as $\left[9+0.8\right]cm=9.8cm$

Therefore, $9cm8mm$ can be written as $9.8cm$.