Maths Trick ==> MULTIPLICATION OF 11 WITH ANY NUMBER

MULTIPLICATION OF 11 WITH ANY NUMBER

Let me explain this rule by taking examples
1) 234163*11 = 2—2+3—3+4—4+1—1+6—6+3—3 = 2575793
Means insert the sum of 2 successive digits and put 2 terminal digits in its place
2) 45345181*11 = 4—4+5—5+3—3+4—4+5—5+1—1+8—8+1—1 = 498796991
EXAMPLE.
Here an extra case arises
Consider the following examples for that
3) 473927*11 = 4+1— (4+7-10) +1— (7+3-10) +1— (3+9-10) +1— (9+2-10)— (2+7) —7 = 5213197
4) 584536*11 = 5+1—(5+8-10)+1—(8+4-10)—(4+5)—(5+3)—(3+6)—6 = 6429896

Maths Trick ==> How to Multiply Double-Digit Numbers by 11

How to Multiply Double-Digit Numbers by 11

 

All you need to do is add the digits of the number you are multiplying by 11 and place that in the middle of the original number. If the sum of the digits is 10 or larger, simply carry it over. Better to see it than me write it.

See how easy that was? Basically, if you know how to add, you know how to multiple by 11.

Now, let’s look at another example.

  • 11 x 11

Just separate the number being multiplied by 11 (in this case, also 11) so that there’s room for your number in-between. Now, just add the two digits in that number together (1 + 1 = 2) and throw the sum in that space you left open. That gives you 121.

  • 58 x 11

Just add 5 + 8, which gives you 13. The slide it in-between the 5 and 8 and you get 5138. But, that’s not right, since you need to carry that one over. Go ahead and carry it over and you’ll end up with 638.

Needless to say, I feel like a complete badass now that I know this.

Maths Tricks ==> MULTIPLICATION OF 2 TWO-DIGIT NUMBERS

MULTIPLICATION OF 2 TWO-DIGIT NUMBERS WHERE THE FIRST DIGIT OF BOTH THE NUMBERS ARE SAME AND THE LAST DIGIT OF THE TWO NUMBERS SUM TO 10

 

Let me explain this rule by taking examples
To calculate 56×54:
Multiply 5 by 5+1. So, 5*6 = 30. Write down 30.
Multiply together the last digits: 6*4 = 24. Write down 24.
The product of 56 and 54 is thus 3024.
EXAMPLE.
Understand the rule by 1 more example
78*72 = [7*(7+1)][8*2] = 5616

Maths Tricks ==> SQUARE OF ANY 2 DIGIT NUMBER

SQUARE OF ANY 2 DIGIT NUMBER

 

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

Maths Trick ==> SQUARE OF NUMBERS NEAR TO 100

SQUARE OF NUMBERS NEAR TO 100

 

Let me explain this rule by taking examples
96^2 :-
First calculate 100-96, it is 4
so 96^2 = (96-4)—-4^2 = 9216
similarly
106^2 :-
First calculate 106-100, it is 6
so 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