Question

Express the following as cm using decimals: 116 mm

Answer 1

Hint: Decimals are an extension of our number system. Decimal has two parts, one is the whole number part and other is the decimal part. These two parts are separated by \[ \bullet \] called decimal points. Just like a regular whole number we can add, subtract, multiply and divide decimals. We know that 10 mm=1 cm. using this we can express 116 mm to cm.

Complete step-by-step answer:
As we know now, \[10\;mm = 1\;cm\].
Divide by 10 on both side, we get:
\[ \Rightarrow 1\;mm = \dfrac{1}{{10}}\;cm\]. ---- (1)
Given, \[116\;mm\], since 1 is multiple of any number.
We can write 116 as \[116 \times 1\]
\[166\;mm = 116 \times 1\;mm\]
Substituting, (1) in above, we get:
\[ = 116 \times \dfrac{1}{{10}}\;cm\]
\[ = \dfrac{{116}}{{10}}\;cm\] (Simple division and multiplication)
\[ = 11.6\;cm\]
Hence, \[116\;mm = 11.6\;cm\].
As we can see in above, if they give any number in millimetre and ask you to express centimetre in decimal. Just divide the given number by 10. For example, to convert 46 mm to centimetre we divide 46 by 10 which gives 4.6 cm. Which is the same for any number. Decimals a number written with a decimal point and a remainder that represents portion of ten.
So, the correct answer is “11.6 cm”.

Note: The above method is only for converting millimetres to centimetre. In the whole number place, we multiply by 10 to get to the next place value. That is tenths, hundredths and so on. In decimal, we go the opposite direction and divide by 10(in above when 116 is divided by 10 we go to the opposite direction in comparison with the whole number part). There are also different types of decimals like terminating and non-terminating decimals.