Divisibility by 2: If its unitâ€™s digit is any of 0,2,4,6,8.
Ex : 100 is divisible by 2 while 101 is not.
Divisibility by 3: If the sum of its digits is divisible by 3.
Ex: 309 is divisible by 3, since sum of its digits = (3+0+9) = 12 , which is divisible by 3.
Divisibility by 4: If the number formed by the last two digits is divisible by 4
Ex: 2648 is divisible by 4, since the number formed by the last two digits is 48 which is divisible by 4.
Divisibility by 5: If its units digit is either 0 or 5.
Ex: 20825 and 50545 are divisible by 5.
Divisibility by 6: If it is divisible by both 2 & 3.
Ex: 53256 is divisible by 6 because it is divisible by 2 as well as 3.
Divisibility by 7: If after subtraction of a number consisting of the last three digits from a number consisting of the rest of its digits the result is a number that can be divided by 7 evenly
Ex.: 414141 is divisible 7 as 414-141= 273 is divisible by 7
Many different ways to test divisibility by seven have been devised. Some are long and complex, a few involve rewriting the digits, and one even consists of a grid-like box. We have chosen one of the more simplistic versions even though in almost every case it is quicker to merely perform long division.
Divisibility by 8: If the last three digits of the number are divisible by 8.
Ex: 3652736 is divisible by 8 because last three digits (736) is divisible by 8.
Divisibility by 9: If the sum of its digit is divisible by 9.
Ex: 672381 is divisible by 9, since sum of digits = (6+7+2+3+8+1) = 27 is divisible by 9.
Divisibility by 10: If the digit at unitâ€™s place is 0 it is divisible by10.
Ex: 69410, 10840 is divisible by 10.
Divisibility by 11: If the difference of the sum of its digits at odd places and sum of its digits at even places, is either 0 or a number divisible by 11.
Ex: 4832718 is divisible by 11, since:
(Sum of digits at odd places) â€“ (sum of digits at even places)
= (8+7+3+4)-(1+2+8) = 11
Divisibility by 12: A number is divisible by 12 if it is divisible by both 4 and 3.
(i) The number formed by last two digits is 32, which is divisible by 4
(ii) Sum of digits = (3+4+6+2) = 18, which is divisible by 3.
Divisibility by 13:Â Remove the last digit of a number. Multiply it by 4 and add it to the remaining truncated number. Â Continue doing these steps until you reach a 2 digit number. If the result is divisible by 13, then so was the first number.
Example: 113945-->11394+20=11414-->1141+16=1157-->115+28=143 (since this number is divisible by 13, you can say 113945 is also divisible by 13)
You can go a step forward
14 + 12 = 26 is 2*13, so 113945 is divisible by 13.
Divisibility by 14: If a number is divisible by 2 as well as 7.
Divisibility by 15: If a number is divisible by both 3 & 5.
Divisibility by 16: If the number formed by the last 4 digits is divisible by 16.
Ex: 7957536 is divisible by 16, since the number formed by the last four digits is 7536, which is divisible by 16.
Divisibility by 24: If a number is divisible by both 3 & 8.
Divisibility by 40: If it is divisible by both 5 & 8.
Divisibility by 80: If a number is divisible by both 5 & 16.
Next in this series, based on your responses, we will share the divisibility rules of 17, 19, 23, 29, 31, 37, 41, 43, 47
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