Most of the exams and test for higher level service or enginerring test or management tests require mathematical skills. That include skill to do fast soltion to elementary maths . The timing is crucial in these exams. So , if you know the fatsest way to multiply or divide , it saves yopu pelnty of time. Today, fastest way to multiply and didvide by 5 is taught. It will take minutes to understand the math trick , but after that you will not need even pen and paper for multiplication by five or didvidion by five.
Math Magic: Division by 5
Suppose you need to divide 1256 by 5 .
Trick : Multiply by 2 , and place a decimal before unit digit
In this case , multiplication with 2 gives result of 2512 .
Place one decimal before unit digit i.e 2 , So the answer is 251.2
Math Magic: Multiplcation by 5
Suppose you need to multiply 1256 by 5 .
STEP 1 : Just half the number i.e divide by 2 . SO in this case 1256/2 = 628
Step 2: If the result after dividing by 2 is whole number [ i.e without any decimal] then place one ZERO after the result . Like in the case of example , the result after halving the number 1256 , is without decimal so , we put one zero at the end and the answer is 6280
However, if the result after halving the number is with any decimal , ignore the decimal and put 5 ate the end .
For example , if you multifply number 121 x 5 , then
Step 1: Halve the number i.e 121/2 = 60.5
Step 2: Ignore any thing written after decimal and just put 5 at the end
So answer is 605
Practice on following fours sums and see how fast you are