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One whole number is divisible by another if the remainder we get after the division is zero.
Examples
36 is divisible by 4 because 36 ÷ 4 = 9 with a remainder of 0.
36 is divisible by 6 because 36 ÷ 6 = 6 with a remainder of 0.
36 is not divisible by 5 because 36 ÷ 5 = 7 with a remainder of 1.
Divisibility Rules
By using divisibility rules, we can easily find whether a given number is divisible by another number without actually performing the division. This saves time especially when working with numbers. Divisibility rules of numbers 1 to 10 are provided below.
 Divisibility Rule Description Examples Divisibility by 2 A number is divisible by 2 if the last digit is even. i.e., if the last digit is 0 or 2 or 4 or 6 or 8 Example 1: Check if 64 is divisible by 2. The last digit of 64 is 4 (even). Hence 64 is divisible by 2 Example 2: Check if 69 is divisible by 2. The last digit of 69 is 9 (not even). Hence 69 is not divisible by 2 Divisibility by 3 A number is divisible by 3 if the sum of the digits is divisible by 3 Please note that we can apply this rule to the answer again and again if needed. Example 1: Check if 387 is divisible by 3. 3 + 8 + 7 = 18. 18 is divisible by 3. Hence 387 is divisible by 3 Example 2: Check if 421 is divisible by 3. 4 + 2 + 1 = 7. 7 is not divisible by 3. Hence 421 is not divisible by 3 Divisibility by 4 A number is divisible by 4 if the number formed by the last two digits is divisible by 4. Example 1: Check if 416 is divisible by 4. Number formed by the last two digits = 16. 16 is divisible by 4. Hence 416 is divisible by 4 Example 2: Check if 481 is divisible by 4. Number formed by the last two digits = 81. 81 is not divisible by 4. Hence 481 is not divisible by 4 Divisibility by 5 A number is divisible by 5 if the last digit is either 0 or 5. Example 1: Check if 305 is divisible by 5. Last digit is 5. Hence 305 is divisible by 5. Example 2: Check if 420 is divisible by 5. Last digit is 0. Hence 420 is divisible by 5. Example 3: Check if 312 is divisible by 5. Last digit is 2. Hence 312 is not divisible by 5 Divisibility by 6 A number is divisible by 6 if it is divisible by both 2 and 3 Example 1: Check if 546 is divisible by 6. 546 is divisible by 2. 546 is also divisible by 3.  Hence 546 is divisible by 6 Example 2: Check if 633 is divisible by 6. 633 is not divisible by 2 though it is divisible by 3.  Hence 633 is not divisible by 6 Example 3: Check if 635 is divisible by 6. 635 is not divisible by 2. 635 is also not divisible by 3. Hence 635 is not divisible by 6 Example 4: Check if 428 is divisible by 6. 428 is divisible by 2 but it is not divisible by 3. Hence 428 is not divisible by 6 Divisibility by 7 To find out if a number is divisible by 7, double the last digit and subtract it from the number formed by the remaining digits. Repeat this process until we get at a smaller number whose divisibility we know. If this smaller number is 0 or divisible by 7, the original number is also divisible by 7. Example 1: Check if 349 is divisible by 7. Given number = 349 34 - (9 × 2) = 34 - 18 = 16 16 is not divisible by 7. Hence 349 is not divisible by 7 Example 2: Check if 364 is divisible by 7. Given number = 364 36 - (4 × 2) = 36 - 8 = 28 28 is divisible by 7. Hence 364 is also divisible by 7 Example 3: Check if 3374 is divisible by 7. Given number = 3374 337 - (4 × 2) = 337 - 8 = 329 32 - (9 × 2) = 32 - 18 = 14 14 is divisible by 7. Hence 329 is also divisible by 7. Hence 3374 is also divisible by 7 Divisibility by 8 A number is divisible by 8 if the number formed by the last three digits is divisible by 8 Example 1: Check if 7624 is divisible by 8. The number formed by the last three digits of 7624 = 624. 624 is divisible by 8. Hence 7624 is also divisible by 8. Example 2: Check if 129437464 is divisible by 8. The number formed by the last three digits of 129437464 = 464. 464 is divisible by 8. Hence 129437464 is also divisible by 8. Example 3: Check if 737460 is divisible by 8. The number formed by the last three digits of 737460 = 460. 460 is not divisible by 8. Hence 737460 is also not divisible by 8 Divisibility by 9 A number is divisible by 9 if the sum of its digits is divisible by 9. (Please note that we can apply this rule to the answer again and again if we need) Example 1: Check if 367821 is divisible by 9 3 + 6 + 7 + 8 + 2 + 1 = 27 27 is divisible by 9. Hence 367821 is also divisible by 9. Example 2: Check if 47128 is divisible by 9 4 + 7 + 1 + 2 + 8 = 22 22 is not divisible by 9. Hence 47128 is not divisible by 9. Example 3: Check if 4975291989 is divisible by 9 4 + 9+ 7 + 5 + 2 + 9 + 1 + 9 + 8 + 9= 63 Since 63 is big, we can use the same method to see if it is divisible by 9. 6 + 3 = 9 9 is divisible by 9. Hence 63 is also divisible by 9. Hence 4975291989 is also divisible by 9 Divisibility by 10 A number is divisible by 10 if the last digit is 0. Example 1:Check if 2570 is divisible by 10. Last digit is 0. Hence 2570 is divisible by 10. Example 2: Check if 5462 is divisible by 10. Last digit is not 0. Hence 5462 is not divisible by 10