Division rules:
Division rules are one of the most important mathematical principals learners should know.
Teachers can teach their learners the rules of division:
Divisible by 2
A number is divisible by 2, if the last digit of the number is a 0, 2, 4, 6, 8 (even numbers)
150÷2=75 therefor 150 is divisible by 2
152÷2=76 is divisible by 2
Divisible by 3
A number is divisible by 3 if the sum of the digits is divisible by 3.
150 = 1 + 5 + 0 = 6 and 6 is divisible by 3
152 = 1 + 5 + 2 = 8 not divisible by 3
19865 = 1 + 9 + 8 + 6 + 5 = 29 and 29 is not divisible by 3
19863 = 1 + 9 + 8 + 6 + 3 =27 and 27 is divisible by 3.
Divisible by 4
A number is divisible by 4 if the last 2 digits of the number is divisible by 4 or if the last 2 digits are 0.
27800 = 6950 divisible by 4 because it ends on 2 zeros
25784 = divisible by 4 because the 4 can be divided into the last 2 digits.
13298 = not divisible by 4 because the last 2 digits are not zeros and 98 cannot be divided by 4
Divisible by 5
A number is divisible by 5, if the last digit of the number is a 5 or a 0.
29180 = divisible by 5 because it ends on a 0
281736 = not divisible by 5, because it ends on a 6.
1823945 = divisible by 5 because it ends on a 5.
Divisible by 6
A number must be divisible with 2 and 3, to be divisible by 6.
150 = 1 + 5 + 0 = 6 and 6 is divisible by 3
150 is even, therefore also divisible by 2
150 = divisible by 6 because it is divisible by 2 and 3
152 = 1 + 5 + 2 = 8 not divisible by 3
152 = even, therefore divisible by 2
152 = not divisible by 6 because 152 is divisible by 2 but not divisible by 3 too.
Divisible by 8
A number is divisible by 8, only if the last 3 digits of the number is divisible by 8, or the last 3 digits are zeros.
112000 = divisible by 8 because the last 3 digits are zeros.
11156 = (156 ÷ 8 =not divisible by 8) therefore 11156 is not divisible by 8.
11168 = (168 ÷ 8 = 21) therefore 11168 is divisible by 8, because the last 3 digits are divisible by 8.
Divisible by 9
A number is divisible by 9, if the sum of the digits is divisible by 9.
1986 = 1 + 9 + 8 + 6 = 24 not divisible by 9 because 24 is not divisible by 9
1989 = 1 + 9 + 8 + 9 = 27 divisible by 9 because 27 is divisible by 9.
Divisible by 10
A number is divisible by 10, only if the last digit of the number is a 0.
11183474 = not divisible by 10 because it does not end on a 0.
11183940 = divisible by 10, because the last digit is a 0.
Divisible by 11
Take the alternating sum of the digits in the number, read from left to right. If that is divisible by 11, so is the original number. So, for instance, 2728 has alternating sum of digits 2-7+2-8 = -11. Since -11 is divisible by 11, so is 2728.
We can also take the sum of the alternating digits: 2728 = 2 + 2= 4 and 7 + 8=15 and subtract the 2 answers.
4 - 15 = -11 and -11 is divisible by 11, therefore the number is divisible by 11.