All Stories

Latest Exam Updates

IBPS Clerk 2021 Notification Out :Latest updates

IBPS Clerk 2021 Notification IBPS (Institute of Banking Personnel Selection) conducts a common recruitment process (CRP) every year to the r...

Showing posts with label division and multiplication shortcuts. Show all posts
Showing posts with label division and multiplication shortcuts. Show all posts

Wednesday, 1 July 2015

Basic Maths Tricks and shortcuts for competitive exams:Multiplication and Division shortcut

Basic Maths Tricks and shortcuts for competitive exams:In every competitive exam, if you want to succeed you should manage your time well.To crack a bank exam , time management is a crucial factor.Understanding some shortcuts and tricks will definitely save your time during common written examinations.Here we are sharing some simple but powerful time saving shortcut tricks for division and multiplication.

1. Division-shortcuts

In division instead of direct division, use factoring method


Example: 78 and 72.  These two numbers, if we add the numbers in the unit's place, the resultant is 10 and thenumbers in the ten's place are both the same. In such cases, we can have a simple solution.
Step1: multiply the numbers in the unit's place and write down the resultant. (8*2 = 16)
Step2: say, the number in the ten's digit is a, then multi a*(a+1) and write down the resultant. => (7*(7+1) = 56)
Step3: write the final result: 5616
Example:118*112 follow above steps
 8*2 = 16; and 11*(11+1) = 11*12 = 132. And hence
the result is: 13216.
In short: ab*ac = (a*(a+1))(b*c)

Base Method:

Base numbers, in general, are nothing but multiples of 10. If the given numbers are nearer to
base numbers, then you can follow this method to multiply them.
Example: 98*95 =?
Here 98 is ,2 less than the base number 100 and 95 is ,5 less than 100. We can write them like this:
98  -2
95  -5
The first step will be deducting/subtracting the resultant of the diff between the base number and the given number with the given number in a cross-way! That is, you need to subtract 98 and 5 (which is the resultant of difference between the base number and 95) or you can also cross-subtract 95 and 2, the result will be same. This result forms the 1st part of the resultant at the start. The last part of the resultant will be multiplication of the differences from base numbers (i.e., 2 * 5 = 10)
98  -2
95  -5
(98 – 5) (-2 * -5)
Hence, the answer will be: 9310

Example: 998*997 =?
998  -2
997  -3
Observe carefully, in the second part, the multiplication of difference yield in a single digit number, but no. of zeroes in the base number, here 1000, is three. Hence add two zeroes before the result. Therefore, the answer will be: (998-3) | (-2 * -3) = 995006
What if the numbers we get are like this? I mean, the base is 50 here. We will follow the same procedure as above but a small difference that the resultant in the first part will be halved. And if the base is 200, then the number will be doubled and so on based on the base number.

Multiplication with 5,25,50 etc...

Substitute 5 by 10/2,25 by 100/4 and 50 by 100/2.

  1. 5*18=18*10/2=180/2=90
  2. 24*25=24*100/4=2400/4=600
  3. 73*50=73*100/2=7300/2=3650

Multiplication with 9, 99,999 etc..

  1. 13*9=13*(10-1)=130-13=117
  2. 26*99=26*(100-1)=2600-26=2574
  3. 350*999=350*(1000-1)=350000-350=349650
Click here for square,square root and cube root shortcuts 
Hope this shortcuts will help you do better.Share it if you find this shortcuts useful.
[Tags:quantitative aptitude tricks and shortcuts pdf,quantitative aptitude tricks and shortcuts pdf free download,quantitative aptitude tricks and shortcuts books,quantitative aptitude tricks and shortcuts for bank exams,quantitative aptitude tricks and shortcuts for cat,quantitative aptitude tricks and shortcuts videos,quantitative aptitude shortcuts and tricks for bank po pdf,quantitative aptitude shortcut methods pdf-tricks to solve download]
simon         6 comments:

Contact Form


Email *

Message *