*How fast can you multiply the following numbers:** *11 * 19 = ?27 * 23 = ?39 * 31 = ?42 * 48 = ?53 * 57 = ?64 * 66 = ? 107 * 103 = ?112 * 128 = ?124 * 126 = ? Well it should not take more than *2-3 seconds β¦

**How fast can you multiply the following numbers:**

**2-3 secondsπ²**for those who know the trick, for those who don't know, even if they apply the direct multiplication method, it will take more than that in most of the cases.

**same**

__1__1 *

__1__9,

__2__7 *

__2__3,

__11__2 *

__11__8,

__12__4 *

__12__6 the first part of the numbers are same,

**exactly**10

__1__* 1

__9__, 2

__7__* 2

__3__, 11

__2__* 11

__8__, 12

__4__* 12

__6__

Only when both conditions are fulfilled, then the method works.

__1__1 *

__1__9 = 2_ ,

__11__2 *

__11__8 = 132_

1__1__ * 1__9__ = 209 , 11__2__ * 11__8__ = 13216

Just understanding the method takes little time, and with little practice you will be applying it with lightning speedπ , just look at the following numbers and i am sure within 2 seconds, you can figure out the answer

11 * 19 = 209

27 * 23 = 621

39 * 31 = 1209

42 * 48 = 2016

53 * 57 = 3021

64 * 66 = 4224

107 * 103 = 11021

112 * 128 = 15616

124 * 126 = 15624

it's easy to learn a few shortcuts a day and practice each for 5-10 minutes, rather than cramming most of them and forgetting the next day, try to apply shortcuts when you solve problems at home, so that you can apply them in exams easily, i am practicing shortcuts and will **post them frequently**, if anyone wants to share special tricks, then please do, u r most welcome. these shortcuts may make the difference in SSC and CAT this year for you, so do not ignore them.

OK friends, so here's the next trick

Well this is very simple and most of us are in fact familiar with it, but if you are not then you will be in a few seconds.

The trick is to find squares of numbers ending in 5. For that just remember 5^2 = 25 (simple)

Now let's take any number ending in 5, say N5, its square will be have last part always as 25, and first part will be (N * N+1).

example, 25^2 has last part as 25, now first part = 2*3=6, hence 25^2 = (__2*3__) 25 = 625

similarly, 35^2 = (__3*4__) __25__ = 1225

45^2 = (__4*5__) __25__ = 2025

125^2 = (__12*13__) __25__ = 15625

and so on π

**Square of Numbers near 100:**

Let me explain this rule by taking examples

96^2 :-

First calculate 100-96,

it is 4so 96^2 = (96-4)----4^2 = 9216

similarly106^2 :-

First calculate 106-100,

it is 6so 106^2 = (106+6)----6^2 = 11236

**Example. ** An other case arises

110^2 = (110+10)----100

= (120+1)----00

= 12100

similarly

89^2 = (89-11)----121

= (78+1)----21

= 7921

**Square of any two digit number: Easiest method **π

Let me explain this trick by taking examples

67^2 = [6^2][7^2]+20*6*7

= 3649+840

= 4489

similarly

25^2 = [2^2][5^2]+20*2*5

= 425+200

= 625

Take one more example

97^2 = [9^2][7^2]+20*9*7

= 8149+1260

= 9409

Here [] is not an operation, it is only a separation between initial 2 and last 2 digits

**Example. **

Here an extra case arises Consider the following examples for that

91^2 = [9^2][1^2]+20*9*1

= 8101+180

= 8281

πππππ

Statutory Warning: Calculators are for Brainless people π

Alright guys.. New trick:Calculate 456456*999999?? Answer can be done in 5 seconds...!!

U read it right ...That's 5 seconds

well the answer is 456455543544...!!!

it took 3 secs for me...now the trick itself :

456456*999999 = 456455543544

step-1: 456456-1= 456455(first half answer)--->A

999999-A= 543544--->B

the Answer is AB= 456455_543544

More Examples:

345*999= 344655 (calculate in mind)

999*999= 998001 (again calculate in mind)

123456789*999999999= 123456788876543211

Amazing Trick right...!!!

Note: number of digits in the no. and 9999...9 should be same.

Statutory Warning: Calculators are for Brainless people Alright guys.. New trick:Calculate 456456*999999?? Answer can be done in 5 seconds...!!

U read it right ...That's 5 seconds

well the answer is 456455543544...!!! it took 3 secs for me...now the trick itself :456456*999999 = 456455543544step-1: 456456-1= 456455(first half answer)--->A999999-A= 543544--->Bthe Answer is AB= 456455_543544More Examples:

345*999= 344655 (calculate in mind)

999*999= 998001 (again calculate in mind)

123456789*999999999= 123456788876543211Amazing Trick right...!!!

Note: number of digits in the no. and 9999...9 should be same.

The sum of thirty-two consecutive natural numbers is a perfect square. What is the least possible sum of the smallest and the largest of the thirty-two numbers?

Here is some of the tricks i learned while preparing.Hope it will Β help.

Strange Facts about Numbers #4 Any even number above 3 can be expressed as sum of two prime numbers. 4 = 2 + 2, 6 = 3 + 3, 8 = 3 + 5, 10 = 5 + 5, 12 = 5 + 7, and so on. It's not proven yet and so is entitled to be a conjecture. Can anyone name this?

Strange Facts about Numbers #5 145 has a unique property, the sum of the factorials of it's digits gives you the number itself. So, 1! + 4! + 5! = 145. Can be useful for XAT alphanumeric questions.#XAT There are a lot of numbers that possess similar property. Can you find any one of them? #Numberrs

For speed maths video tutorial , i think this playlist is really help , it has videos on quick addition , subtraction and multiplication . Best speed maths tricks for fast calculation | Vedic maths | Quick solving: https://www.youtube.com/playlist?list=PLnNa3uNHAm1JBdoM5cmcXeU2qs6lbV_92

A good source/book for clearing concepts and practice for Quant chapters like Permutation and Combination, Probability, Mensuration ??Β