Section 2.1 Divisibility Rules Chapter 2 Section 2.1 Divisibility Rules

Rule for 2 If the number ends with an even digit (like 2,4,6,8,0), then it is divisible by 2. Example: 1,354,908

Rule for 5 If the number ends with a digit of “5” or “0”, then the number is divisible by 5. Example: 3,627,905 8,394,410

Rule for 10 If the number ends in a “0” digit, Then the number is divisible by 10. Example: 750,230

Rule for 3 If you add up the digits of the number and the total is divisible by 3, Then the original number is divisible by 3. Example: 1,248 = 1+2+4+8 =15. 15 is divisible by 3, therefore so is 1,248!

Rule for 9 If you add up the digits ofthe number and the total is divisible by 9, Then the original number is divisible by 9. Example: 6,543 = 6+5+4+3 =18. 18 is divisible by 9, therefore so is 6,543.

Rule for 4 If the last two digits in the number are divisible by 4, Then the original number is divisible by 4. Example: 358,912 12 is divisible by 4, therefore so is 358,912!

Rule for 6 If the number is divisible by 2 and 3, then it is also divisible by 6. Example: 8,346. 8,346 = last digit even (divisible by 2) 8,346 = 8+3+4+6 = 21 (divisible by 3) So also divisible by 6!