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.