Divisibility Test - 2

 Divisibility Test Of 2,4,8,5,10 And 15  

A  number is said to be divisible by another number if the remainder is 0.  Divisibility rules are a set of general rules that are often used to determine whether or not a number is evenly divisible by another number. Divisibility Rules.

Divisibility Test of 2 : 

A number is divisible by 2 if the number is even
  Example . 126,434,22,54988

Divisibility Test of 4:

 A number is divisible by 4 if last two digit is divisible by 4

 ( In vedic math there is  one more trick ." Ultimate and twice penultimate " this  formula use here)

Example: 12376, 544,5692

Divisibility Test of 8: 

 A number is divisible by 8 if last three digit is divisible by 8 
Example : 3424, 5648, 67856..

Divisibility Test of 5:

A number is divisible by 5 when in unit digit there have 5 or 0
Example : 4455,4590,3480.35565..

Divisibility Test of 10:

A number is divisible by 10 when in unit digit there have only 0
Example : 44550,4590,3480,35560..

Divisibility Test of 15:   5*3=15
A number is divisible by 15 when 
1)  There should be 5 or 0 in unit place
2) Digit sum must be 3 or 6 or 9
Example : 5610,555,2220

Exercise:

Test the divisibility of 2,3,4,5,6,8,9,15,18.of the following numbers .

Practice : 12891,  9361, 243,135795, 41261

Divisibility Tests	Example
A number is divisible by 2  if the last digit is 0, 2, 4, 6 or 8.	168 is divisible by 2 since the last digit is 8.
A number is divisible by 3  if the sum of the digits is 3 or 6 or 9	168 is divisible by 3 since the sum of the digits is 15 (1+6+8=15), and 15 is divisible by 3.
A number is divisible by 4  if the number formed by the last two digits is divisible by 4.	316 is divisible by 4 since 16 is divisible by 4.
A number is divisible by 5  if the last digit is either 0 or 5.	195 is divisible by 5 since the last digit is 5.
A number is divisible by 6  if it is divisible by 2 AND it is divisible by 3.	168 is divisible by 6 since it is divisible by 2 AND it is divisible by 3.
A number is divisible by 8  if the number formed by the last three digits is divisible by 8.	7,120 is divisible by 8 since 120 is divisible by 8.
A number is divisible by 9  if the sum of the digits is divisible by 9.	549 is divisible by 9 since the sum of the digits is 18 (5+4+9=18), and 18 is divisible by 9.
A number is divisible by 10  if the last digit is 0.	1,470 is divisible by 10 since the last digit is 0.

Summary: Divisibility tests can be used to find factors of large whole numbers quickly, and thus determine if they are prime or composite. When working with large whole numbers, tests for divisibility are more efficient than the traditional factoring method.