Question

Find the sum by suitable rearrangement $$238+695+162$$.

Answer 1

Hint: Suitable rearrangement helps in simplifying the question and hence we get quick answers. In this method, we put together those numbers whose sum of unit digits is equal to $$10$$.

Complete step-by-step solution -
In the given question $$238+695+162$$
We group $$238$$ and $$162$$ and add them.
We are doing so because the unit digit of $$238$$ is $$8$$ and of $$162$$ is $$2$$
Sum of their unit digits is $$8+2=10$$
This simplifies our calculation.
We add $$238$$ and $$162$$ initially
$$\Rightarrow 238+162=400$$
Their sum is $$400$$. Then we add the third number to this sum i.e $$695$$
So add $$400$$ and $$695$$
$$\Rightarrow 400+695=1095$$
We got the sum of three given number as $$1095$$
The answer to the given question is $$1095$$.

Note: In this method of suitable rearrangement the unit digits that should be grouped and added first are $$\text{(1+9) ,(2+8) ,(3+7) ,(4+6) ,(5+5)}$$ gives sum as $10$. These unit digited numbers should be added first and then the other numbers should be added.