# Divisibility Rules For 13

Divisibility rule has come into the light to solve large numbers of division problems in an easy way. This rule has come to check whether an integer (dividend) can be completely divided by any other integer(divisor) or not. Suppose if the number is very large and has to be divided by 13 since the number is big and if we apply the division method to check its divisibility, it will take more time. Therefore, the divisibility rules for 13 were introduced.

Apart from 13, we have divisibility rules for 2, 3,4, 5, 6, 7, 8, 9, 10, and so on. For example, in case of divisibility by 2 rule, 82 is a number which is completely divided by 2 as the digit in unit place is even and all the even numbers are divided by 2. But if the number in unit place is odd, then it cannot be completely divided by 2. By this simple rule, we can configure if any number is completely divided by 2 or not.

## Different Divisibility Rules For 13

There are basically 4 types of divisibility rules for 13. Let us explain to you with examples one by one.

Divisibility Rule 1: For a given number, form alternating sums of blocks of three numbers from the right and moving towards the left. Suppose ( $n_{1}n_{2}n_{3}n_{4}n_{5}n_{6}….$ ) is a number N, then if number formed by the alternative sum of blocks of 3-3 digits from the right to the left ($n_{1}n_{2}n_{3}-n_{4}n_{5}n_{6}+…$ ) is divisible by 13 then N is divisible by 13.

Example: Let a number is 2,453,674. Find out it is divisible by 13 or not.

Solution: By applying Rule 1,

674-453+2=223 is not divisible by 13

Therefore, 2,453,674 also is not divisible by 13

Divisibility Rule 2: If a number N is given, then multiply the last digit of N with 4 and add it to the rest truncate of the number. If the outcome is divisible by 13 then the number N is also divisible by 13.

Example: Let a number is 650. Find whether it is divisible by 13.

Solution: By applying Rule 2,

650: 65+0*4=65 and number 65 is divisible by 13 and gives divisor as 5.

Therefore, 650 is also divisible by 13.

Divisibility Rule 3: For a number N, to check whether it is divisible by 13 or not, subtract the last 2 digits of the number N from the 4 times multiple of rest of the number.

Example: Let a number is 728. Check whether it is divisible by 13 or not.

Solution: By applying divisibility by 13 rule, we get,

728: 7*4-28=28-28=0 and number 0 is divisible by 13 giving the result as 0.

Divisibility Rule 4: Multiply the last digit by 9 of a number N and subtract it from the rest of the number. If the outcome is divisible by 13 then the number N is divisible by 13.

Example: A number is 858. Find its divisibility by 13 is possible or not.

Solution: By applying rule4,

858: 85-8*9= 13, and 13 is divisible by 13.

Therefore, 858 is divisible by 13.