Question

Imagine that the distance from school to your friend’s home is 2250m. State this in kilometres.

Answer 1

As we can see that the conversion is from smaller units to larger units, we need to divide by a certain factor to get the desired result.

Complete step by step solution:
To begin with, if we are to find the distance in kilometres, then we must know the relation between metres and kilometres. Let us first make it clear that both metre and kilometre are the units that are used to measure distance or displacement. But in the International System of Units, the unit metre is commonly used and it is the accepted unit for most of the calculations. However, kilometre is also used for representing sometimes bigger distances.
Other than metre and kilometre, there are many other units which are interconvertible to one another.For instance, let us find a relation between metre and kilometre.
We know, $1000$ metre is equal to one kilometre.We will use the conventional unitary method to find the result.Mathematically, we can write as follows:
$1000\,{\text{m}}$ is equal to $1\,{\text{km}}$ .
So, $1\,{\text{m}}$ is equal to $\dfrac{1}{{1000}}\,{\text{km}}$ .
Therefore, $2250\,{\text{m}}$ is equal to $2250 \times \dfrac{1}{{1000}}\,{\text{km}}$.
$2250 \times \dfrac{1}{{1000}}\,{\text{km}} \\\ \Rightarrow\dfrac{{2250}}{{1000}}\,{\text{km}} \\\ \therefore 2.25\,{\text{km}}$

Hence, $2250\,{\text{m}}$ is equivalent to $2.25\,{\text{km}}$.

Note: While answering this question, most of the students while making haste, seem to multiply the given magnitude in metres with a factor $1000$,which is wrong. First, we have to observe the unit given in the question and then proceed. If you are converting smaller units to larger units then we have to divide and if we are converting larger units to smaller units then we have to multiply.