Learning to perform fast mental maths calculation will help you immensely irrespective of which field of life you deal with.Knowing these mental maths tricks will give you a positive edge over the others.Whether you are a student,aspiring engineer,statistician,scientist,school teacher or anyone else dealing with numbers,learning this quick mental tricks and techniques
You must have heard of Shakuntala Devi-the lady who performed maths calculations faster than a Computer,you can do it too, just with a little bit of practice.
For example, let say you want to multiply 52*11.This can be calculated in less than 1 second but if you want to do it traditionally,it will take you around 5-6 seconds.Isn’t it?
So let see how using a simple mental maths trick,this calculation can be done in a matter of seconds…
To multiply 52 and 11,imagine there is a space between 52
52*11= 5_2 (Put an imaginary space in between)
Now,what to do with that space?
Just add 5 and 2 and put the result in the imaginary space
So, 52 * 11 =572 (which is your answer)
Isn’t it great?
Lets try some more examples:
1) 35 * 11 = 3 (3+5) 5 = 385
2) 81 * 11 = 8 (8+1) 1 = 891
3) 72 * 11 = 7 (7+2) 2 = 792 etc..
With just a little bit of practice you can easily perform these simple mental maths tricks in the blink of an eye.
People sitting for competitive exams often complain that they could not complete the Question paper within a certain time period as the paper was too length(l)y.But for your information,let me tell you that all papers of all competitive exams are so designed that students can finish it within the given time period.Its just that student do not have the required efficiency.So in tight time constraint situation where time plays a very important role,knowing these quick mental maths techniques will give you an edge over your competitors.It will be your X-Factor.It will give you that sharpness and smartness required to crack any competitive exams.
Lets take an example of this sum which has been taken from the 2010 question paper of a Popular Bank PO Examination (Aptitude Section):
(Q) Is 456138 divisible by 9?
Now, it only takes 2 seconds for you to determine the answer.But if you go by the traditional way then it will take you 10 seconds.So you can see the difference.Those 8 extra seconds you win,you can spend on other question.Isn’t it?
No let see the solution
(Answer) To test whether a certain large number is divisible by 9 or not,’just add all the digits of the number and if the end result is divisible by 9,then you can say that the entire large number will be divisible by 9 too‘.
Now since 27 is divisible by 9 so 456138 will be divisible by 9 too.
By now you must have some idea, how important it is to know these mental maths tricks.Knowing these simple calculation techniques gives you an advantage over others and can get you a job,get you crack any competitive exams and much more.
Here are few more mental maths tricks..
Multiply any large number by 12 mentally in seconds
To multiply any number by 12 just double last digit and thereafter double each digit and add it to its neighbour
For example 21314 * 12 = 255768
Lets break it into simple steps:
Step 1: 021314 * 12 = _____8 (Double of Last Digit 4= 8 )
Step 2: 021314 * 12 = ____68 (Now Double 1= 2, and add it to 4, 2+4=6)
Step 3: 021314 * 12= ___768 (Now Double 3=6, and add it to 1, 6+1=7)
Step 4: 021314 * 12= __5768 (Now Double 1=2, and add it to 3, 2+3=5)
Step 5: 021314 * 12= _55768 (Now Double 2=4, and add it to 1, 4+1=5)
Step 6: 021314 * 12= 255768 (Now Double 0=0, and add it to 2, 0+2=2)
So your final answer of 21314 * 12 = 255768
Calculating Square of numbers quickly…
Lets calculate the square of 54
So (54)^2 = 5^2 +4 — 4^2 = 25 +4 —-16 =29——-16= 2916
Similarly (55)^2 = 5^2 +5 –5^2=25+5——25=30———25= 3025
Similarly (56)^2 = 5^2 + 6–6^2=25+6——36= 31——–36= 3136 etc..
Similarly try out squares of 57,58 etc..
These are just few of the many Mental Maths Tricks possible.