How to test for divisibility by 3 from taking user input and sum the digits

Question

A common test for divisibility by 3 is to add the digits of an integer. If the resulting sum is
divisible by 3 then so is the original number. Program this test. The sum must be < 20 i.e. if
the sum is >= 20, then the digits of the resulting sum must be added. It should repeat this
procedure until the sum is < 20. The program should input a number from the user and print
out whether or not the number is divisible by 3

Answer 1

Why would you sum these digits? Just use modulo.

Anyway, if I had to, I would take input as string, iterate thru it casting each position to int and adding them to sum

Answer 2

It would be 0

Answer 3

Minenhle Simphiwe so I gave you an idea with string, you can do it using for loop

Answer 4

What does the modulo(%) operator do ?

Answer 5

it returns the remainder

Answer 6

And what will be the remainder if the number is perfectly divisible ?

Answer 7

Juan Pablo Segundo
I wanna use the 3 divisibility Rule actually that's why I sum the digits I wanna know how to use the for loop to come to an answer

Answer 8

Arvind
Your Code Will Run But It Will Only Display True Or False Then The int input Is Entered..Thanks Though

Answer 9

Arvind Okey Thank You