Divisibility Test

DRules

 

 

 

 

 

 

 

 

 

A number is divisible by 2 if the number is even (last digit is 0, 2, 4, 6, or 8).

A number is divisible by 3 if the sum of digits is divisible by 3.  This process can be repeated. Example: is 1997 divisible by 3? Now 1+9+9+7=26, and 2+6=8 which is not divisible by 3. Therefore 1997 is not divisible by 3.

A number is divisible by 4 if the number formed by the last two digits is divisible by 4. (even0, even4, even8, odd2, odd6). Example:    3728 is a divisible by 4 because 28 is.

A number is divisible by 5 if the last digit is 0 or 5. Example:    125 is a divisible by 5 because the last digit is 5.

A number is divisible by 6 if is divisible by 2 and 3 (even, and sum of digits is divisible by 3). Example:    900 is divisible by 6 because its last digit is even and the sum of its digits (9 + 0 + 0 = 9) is divisible by 3.

A number is divisible by 8 if the last three digits divide by 8.

A number is divisible by 9 if the sum of digits is divisible by 9. Example:  8,721 is divisible by 9?  First, add the digits: 8+7+2+1=18. Since 18 is divisible by 9, the entire number is too!

A number is divisible by 10 if the last digit is 0.

Divisibility Rules Poem

I’m # 2 and I’ll be your friend, as long as an even # is on the end,

#3 will work for me, you see, if the sum is divisible by 3.

The #4 won’t be such a chore, if the last two are divisible by 4,

The #5 is my biggest hero, he has to end in 5 or 0.

The #6 will always go into me, as long as so does 2 and 3.

#9 will go into me just fine, if the sum is divisible by 9.

I’m #10 and this you should know, I always end in a big fat zero!

 

WN32 Divisibility Test

 

Divisibility Help

Divisibility Writing