the sum of its digits is divisible by 3;
the last two digits are divisible by 4 or the sum of the last (units) digit and twice the tens digit is divisible by 4;
Where a sum is required to be divisible, the sum can be tested in the same way; repeating the rule until a single digit remains makes it easy to check.
Where there are 2 alternative rules (for 4 and 8) I've given the "standard" rule (ie the one I was taught) first followed by an alternative rule I've since discovered that is much easier.
The rule for 7:
There is no simple rule for divisibility by 7 and most of the invented rules often take just as long as (if not longer than) dividing the original number by 7.
The best I can offer for 7:
for example: is 5678534 divisible by 7?
5678534 → 5,678,534
→ [0x2 + 0x3 + 5] - [6x2 + 7x3 + 8] + [5x2 + 3x3 + 4]
→ 5 - 41 + 23 = -13 which is not divisible by 7, so 5678534 is not divisible by 7.
The rule for 11 is also expressed as:
Alternately subtract and add the digits from the right hand end of the number; if the result is 0 or divisible by 11, the original number is divisible by 11.
The divisibility rules of 4 and 9 are combined to make the divisibility rule of 36.
The answer will depend on the divisibility rules list.
fractions help you write out divisibility rules because divisibility rules help with fractions . Glad I would help good bye
I
12
The divisibility rules of 4 and 9 are combined to make the divisibility rule of 36.
The answer will depend on the divisibility rules list.
fractions help you write out divisibility rules because divisibility rules help with fractions . Glad I would help good bye
I
The divisibility rules for a prime number is if it is ONLY divisible by 1, and itself.
Jason Delaware
12
You can always check on the divisibility of a number by dividing it into another number. But if you know the divisibility rules, you can get that information easier and faster.
use divisibility rules to find at least four factors of the number 19
i think divisibility rules help with fractions because it helps you reduce the fraction to make i a simple fraction.
Three
3 and 9. And they divide into 123456789 whether or not you use divisibility rules!