Many of us don't know or have forgotten whether any given number is divisible by another given number. Can you say, on observing, any number between 2 and 12 is a factor of any other given number?  If not, let us recollect what we studied or heard by going through the following.

 a)  Divisibility by 2:-   All the even numbers are divisible by 2. i.e.2 is a factor of all the even numbers. e.g. 2452, 93476.

 b)  Divisibility by 3:-  If the sum of all the digits in the given number is divisible by 3, then the given number is divisible by 3.  e.g. 475971.   Here, the sum of the digits  4 + 7 + 5 + 9 + 7 + 1  is 33 and 33  is divisible by 3  i.e. 3 x 11 = 33. So, 475971 is divisible by 3.

 c)  Divisibility by 4:-  If the last two digits of any number taken together is divisible by 4, then the number is divisible by 4. e.g. "247964". Here the last two digits i.e. 64 is divisible by 4 (4 x 16). So the number 247964 is divisible by 4.

 d)  Divisibility by 5:-  Very easy to remember. If the given number ends with either '5' or '0', then such numbers are divisible by "5". e.g. 349735, 73254140.

 e)  Divisibility by 6:-  If the number is divisible by 3(see b) and the given number is an even number, then such numbers are divisible by '6'. e.g.4362246, 942.

 f)  Divisibility by 8:-  It is same like '4' but with a slight variation. If the last 3 digits of any number taken together is divisible by '8', then that number is divisible by '8'.  e.g. 3745760.   Here, the last 3 digits, 760  is divisible by '8'. So, 3745760 is divisible by "8".

 g)  Divisibility by 9:-  Again it is same like '3' but with a slight variation. If the sum of all the digits in the given number is divisible by '9', then the given number is divisible by 9.  e.g. 749655.

 h)  Divisibility by 10:-  This is also very easy. All numbers that end with '0' are divisible by '10'. e.g. 10900, 4980.

 i)   Divisibility by 11:-  If the difference between the sum of all the alternate digits in a number and the sum of left over digits are equal to "0" or in multiples of 11, then the number is divisible by ll. e.g. 1386, 4895209.

 j)   Divisibility by 12:-  If any number is divisible by 3 and is also divisible by 4, then that number is divisible by 12. For divisibility of 3 and 4 refer (b) and (c) above. e.g. 3289764. Check whether this 3289764 is divisible by 3. It is divisible. Now check whether the same number is divisible by 4. It is divisible by 4 also. So the number is divisible by "12". How easy it is?