Vedic / Quicker / Shortcut Math ⇒ Topic : Multiply Any Number with 99 series

Ex 1 : 453 X 999 = ?
Vedic method 
= 453 X (1000 - 1)
= 453000 - 453
= 452547
Answer actually in two parts 452 & 547
first part 453 - 1 = 452
second part 547 = (1000 - 453 = 547) or (9910 - 453 = 547) or (999 - 452 = 547)

Watching 453 do following steps it in your mind : 
Step I. So in easy way reduce 1 from number = 453 - 1 = 452
Step II. (9 - 4) (9 - 5) (10 - 3) = 547 or (9 - 4) (9 - 5) (9 - 2) = 547
Step III. Combine step I & II as 452547

▷ Multiplication of number by greater no. of 9's :

Ex 1 : 453 X 9999 = ?
Ex 1 : 453 X 99999 = ?
Here 453 is three digit number 9999 having four digit or 99999 having five digit
Vedic method 
put as many zero's(0) before value (453) as there are 9's
Like 0453 X 9999 or 00453 X 99999 

Use earlier mentioned steps in your mind
Now = 0453 X 9999
= 453 - 1 = 452 and (9 - 0) (9 - 4) (9 - 5) (10 - 3) = 9547
= 4529547

Or = 00453 X 99999
= 453 - 1 = 452 and (9 - 0) (9 - 0) (9 - 4) (9 - 5) (10 - 3) = 99547
= 45299547

▷ Multiplication of number by lesser no. of 9's :

Ex 1 : 453 X 99 = ?
Step I. First break 453 into two parts 4 and 53(right side pair)
Step II. Now increase 4 by 1 = 5 and subtract it from value(453) say 453 - 5 = 448 
Step III. And subtract 53 from 100 say 100 - 53 = 47 in your mind
Step IV. Combine step II & III as 44847

Ex 2 : 12453 X 99 = ?
Step I. First break 12453 into two parts 124 and 53(right side pair)
Step II. Now increase 124 by 1 = 125 and subtract it from value(12453)
          say 12453 - 125 = 12328 
Step III. And subtract 53 from 100 say 100 - 53 = 47 in your mind
Step IV. Combine step II & III as 1232847