Divisibility Rules

   1. All whole numbers are divisible by 1.
   2. All numbers with a ones digit of 0, 2, 4, 6, and 8 are divisible by 2.
   3. A number is divisible by 3 if its digits add up to a number divisible by 3. For example, 6,711 is divisible by 3 because 6 + 7 + 1 + 1 = 15, and 15 is divisible by 3.
   4. A number is divisible by 4 if its last two digits are divisible by 4. For example, 78,052 is divisible by 4 because 52 is divisible by 4. But 7,850 is not divisible by 4 because 50 is not divisible by 4.
   5. A number is divisible by 5 if it ends in 0 or 5.
   6. A number is divisible by 6 if it is even and also divisible by 3.
   7. Sorry. There are no rules for 7.
   8. A number is divisible by 8 if its last three digits are divisible by 8. For example, 905,256 is divisible by 8 because 256 is divisible by 8. But 74,513 is not divisible by 8 because 513 is not divisible by 8.
   9. A number is divisible by 9 if its digits add up to a number divisible by 9. For example, 1,458 is divisible by 9 because 1 + 4 + 5 + 8 = 18 and 18 is divisible by 9.
  10. A number is divisible by 10 if it ends in 0.