Is 2340 divisible by 9how do you know?

Answer 1

Yes, to test for divisible by 9: add the digits together [2+3+4+0=9]. If the sum equals nine, or a number divisible by nine, then the original number is divisible by nine.

Example: 4752; 4+7+5+2 = 18, which is divisible by 9. If you're not sure, 1+8=9. You can always keep adding the digits together, and eventually you'll be left with a single digit number. If the sum is equal to 9, then the original number is divisible by 9.