Question

Express as cm using decimals.
(1).5mm
(2).60mm
(3).9cm8mm
(4).93mm

Answer 1

Hint: The above question is based on the concept of unit conversions. The main approach towards solving this is by using the conversion unit from millimeters to centimeters and accordingly convert in such a way that we multiply the number with the conversion unit and then convert from fraction into the decimal number.

Complete answer:
A method for converting from unit to other unit is called a conversion unit also called dimension analysis. Converting the units sometimes better helps us in knowing and understanding the measure of things better than the current unit being converted rather than the unit before conversion.
For example, the height of a person if expressed in feet will be a bit difficult to imagine. But if the same height is being converted into centimeters it is easy to understand the height with this unit.
Now, we know the conversion unit from kilometers to meters.
\[1mm = \dfrac{1}{{10}}cm\]
1)So, by applying it on the first number.
\[5mm = 5 \times \dfrac{1}{{10}}cm = \dfrac{5}{{10}} = 0.5cm\]
2)Now applying on the next number
\[60mm = \dfrac{{60}}{{10}}cm = 6.0cm\]
 Writing 6 and 6.0 are the same.3)The next number is 9cm8mm can also be written as
\[ 9cm8mm = 9cm + \dfrac{8}{{10}}cm \\
                      = \left( {9 + \dfrac{8}{{10}}} \right)cm \\
                      = \left( {\dfrac{{90 + 8}}{{10}}} \right)cm \\
                      = \left( {\dfrac{{98}}{{10}}} \right)cm \\
                      = 9.8cm \\
 \]
4)\[93mm = \dfrac{{93}}{{10}}cm = 9.3cm\]
Hence these are the above converted values.

Note:
An important thing to note is that one millimeter is equal to \[\dfrac{1}{{10}}\]cm. Since the metric system is based on decimals so in this case the actual unit is 10mm in one centimeter. It is represented mathematically as \[10mm = 1centimeter\]