Short-cuts for division-Divisibility test Tricks
Division is one of the basic concepts of Mathematics or we can say Calculation. Division is easy but it gets complex when we have to find out result for division of higher number. So, here we are going to introduce with short formulas as well as Divisibility test. Sometimes, Examiners directly asks about divisibility test of number and we consume so much time in a silly question. Here, we are presenting you some tricks so that you don’t speed more than 10-15 seconds to find whether it is divisible by any number form 1 to 10 or not.
Important Tricks about Divisibility Test
If examiner asks you question whether x is divisible by y or not. It means they are directly asking for divisibility test.
Divisible by 2
- If last digit (Unit Digit) of any number is even we can say Number is divisible by the 2. ( Rule is Clear, No example needed).
Divisible by 3
- Count sum of all digits of the given number ( if you get sum in two digits, sum again); If result is either 3 or 6 or 9; Number is divisible by 3 otherwise not.
Check 9653 is divisible by 3 or not.
As sum of all digits is 23; Sum again, you will get 5 as answer which is not divisible by 3. It means 9653 is not divisible by 3.
Divisible by 4
- If last 2 digit of given number is divisible by 4; entire number is divisible by 4.
Check 898128473748 is divisible by 4 or not.
As last two digits of this number is exactly divisible by 4, it means whole number is divisible by 4.
Divisible by 5
- If unit digit (last digit) is either 0 or 5, Number is divisible by 5. (Rule is Clear, No example needed).
Divisible by 6
- First of all check if it is even number. After that, check sum of all digits up to unit digit; if it is either 6 or 9; whole number is divisible by 6.
Check 798172895 is divisible by 6 or not.
As number is odd, it is strictly not divisible by 6.
Check 7981265376 is divisible by 6 or not.
As number is odd, apply next step.
Sum of all digits is 54 and in unit digit, it is 9. It means whole number is divisible by 6.
Cross-check it by your calculator for Confirmation.
Divisible by 6
- Divide whole number in diff. groups of 3-3 digits starting from the right. Add alternate groups and subtract from each other groups. If difference between groups is 0 or multiple of 7, Number is divisible by 7 otherwise not. (This method is applicable only if number had more 4 or more than 4 digits. )
We know above rule is little bit complex; let’s try to understand it by example.
Check 58556344 is divisible by 7 or not.
Divide Number into diff. groups of 3-3 digits starting from the right.
So sum of alternate groups i.e; First with third and second alone.
First + Third: 344+58= 402
Step 3: Subtract from each other.
Step 4: Check whether result is divisible by 7 or not.
As 154 exactly divisible by 7; So above give number is also divisible by 7.
Divisible by 8
- Rule is too much easy. Just check last 3 digits of given number is divisible by 8 or not. You will come to know whether it is divisible by 8 or not.
Divisible by 9
- This one is also easy. Just check sum of all digits of given number and check whether it is divisible by 9 or not. You will come to know whole number is divisible by 9 or not.
Divisible by 11
- Calculate sum of the alternate digits and check difference between both sums if it is 0 or divisible by 11. Then, the entire number is divisible by 11.