TESTS OF DIVISIBLITY
I. Divisibility by 2 :
A number is divisible by 2 if its unit digit is any of 0, 2, 4, 6, 8.
Ex. 58694 is divisible by 3.
II. Divisibility by 9:
A number is divisible by 3 only when the sum of its digits is divisible by 3.
In the numbers 695421, the sum of digits =27, which is divisisible by3.
695421 are divisible by 3.
(III) In the number 948653, the sum of digits = 35, which is not divisible by 3.
948653 is not divisible by 3.
Iv. Divisibility by 4:
A number is divisible by 4 is the sum of its last two digits is divisible by 4.
Ex. (I) 6879376 is divisible by 4, since 76 is divisible by 4.
(II) 496138 is not divisible by 4, since 38 is not divisible by 4.
V. Divisibility by 8:
A number is divisible by 8 if the number formed by hundred’s ten’s and unit’s digit of the given number is divisible by 8.
Ex. (I) in the number 16789552, the number formed by last 3 digits namely 352 is divisible by 8.
16789652 is divisible by 8.
(II) in the number 576484, the number formed by last 3 digits, namely 484 is not divisible by 8.
576484 is not divisible by 8.
VI. Divisibility by 10:
A number is divisible by 10 only when its unit digit is 0.
