Express as cm using decimals: - 5mm

Hint: Check-out the different units of measurement of distance and the relation between them. Observe the relationship of conversion of units from centimeters to millimeters. Use the information: - 1cm = 10 mm to calculate the correct answer.

Complete step-by-step solution
Here, we are provided with a length of 5mm and we have to convert it into cm, that is from millimeter to centimeter. First, let us see the definition of length or distance and the units needed to measure it.
Distance is a numerical measurement of how far apart objects or points are. In physics length or an estimation based on other criteria. Various fields have various formulas for measuring the distance between two points, however, the units used to represent them are the same.
Now, there are various units to represent the distance between two points that depends upon the extent of separation of the points. For example: - small distances are measured in units like millimeters, centimeters, feet, decimetres, etc. And large distances are measured in units like hectometres, kilometers, miles, etc. Here our main concern is to find the relationship between centimeters and millimeters. So, the conversion formula is given as - 1 cm = 10mm, that is one centimeters measures ten millimeters.
Now, let us come to the question. We have been provided 5mm. So, we have,
\[\begin{align}
  & \Rightarrow 10mm=1cm \\
 & \Rightarrow 1mm=\dfrac{1}{10}cm \\
 & \Rightarrow 5mm=\dfrac{5}{10}cm \\
 & \Rightarrow 5mm=0.5cm \\
\end{align}\]
Hence, 5mm is equivalent to 0.5cm.

Note: One must remember the relationships between several units of distance measurement because there will be many questions in which we will be required for the conversion. Remember the conversion of basic units like a millimeter, centimeter, meter, and kilometer. You may apply a unitary method for getting the answer just like we did above but remembering the formulas of conversion will save our time in solving such questions.