Question:
Find the remainder when 51439786 is divided by 3. Do this without performing actual division.
Solution:
Sum of the digits of the number $51439786=5+1+4+3+9+7+8+6=43$
The remainder of 51439786 , when divided by 3 , is the same as the remainder when the sum of the digits is divided 3 .
When 43 is divided by 3, remainder is 1 .
Therefore, when 51439786 is divided by 3 , remainder will be 1 .