To find the remainder of a number divided by 3, add the digits of the number and divide it by 3. So if the digits added together equal 8 then the number has a remainder of 2 since 8 divided by 3 has a remainder of 2.
For example, find the remainder on dividing 1,342,568 by 3.
The digit sum of 1342568 is 1+3+4+2+5+6+8 = 29.
Again, the digit sum of 29 = 2+9 = 11 = 2
So, the remainder will be 2.
Another example: Take 34,259,677,858.
The digit sum of the number is 3+4+2+5+9+6+7+7+8+5+8 = 64.
Now, the digit sum of 64 is 6+4 = 10 = 1.
So, the remainder is 1.
Similarly, the digit sum of 54,670,329,845 is 53 i.e. (5+3=) 8.
When we divide 8 by 3, we get remainder 2.
So the answer will be 2.