CA Final Download the best Free CA FINAL android app for cracking your exam! Download Now
They are the best ca final faculties in India. They have produced many toppers & rank holders. Their video classes are available only here -
CHECK VIDEO CLASSES HERE

# Banking Exam Preparation – “MULTIPLICATION” Part I

## Banking Exam Preparation – “MULTIPLICATION” Part I

Remember some important formula –

1. (a + b)2  = a2 + 2ab + b2
2. (a + b)2  = (a – b)2 + 4ab
3. (a – b)2 = a2 – 2ab + b2
4. (a – b)2 = (a + b)2  – 4ab
5. a2 –b2 = (a – b)(a + b)
6. (a + b)3  = a3 + b3 + 3ab(a + b) = a3 + b3 + 3a2b + 3ab2
7. (a – b)3 = a3 – b3 – 3ab(a – b) = a3 –  b3 – 3a2b + 3ab2
8. a3 + b3  = (a + b)3 – 3ab(a + b)
9. a3 + b3  = (a + b)( a2 – ab + b2  )
10. a3 – b3 = (a – b)3 + 3ab(a – b)
11. a3 – b3 = (a – b)(a2 + ab + b2)
12. am x an = am+n
13. am / an = am – n
14. (a/b)(m/n) =(b/a)-(m/n)
15. am / b-n = am x bn

Banking Exam Preparation – “MULTIPLICATION” Part I

Multiply any two digit numbers

AB x CD = 100(A x C) + 10{(A x D) + (B x C)} + B x D

E.g. 43 x 58 = ?

43 x 58 = 100(4 x 5) + 10{(4 x 8) + (3 x 5)} + 3 x 8

= 100 x 20 + 10{32 + 15) +24

= 2000 + 10{47} + 24

= 2000 + 470 + 24

= 2470 + 24

= 2494

You can get answer in less than 8 seconds by practice more and more.

Banking Exam Preparation – “MULTIPLICATION” Part I

Two numbers that differ by 1

E.g.         45 x 44 = ?

Square larger number and less large number

452 = 2025

2025 – 45 = 1980

E.g.         45 x 46 = ?

Square smaller number and add smaller number

452 = 2025

2025 + 45 = 2070

Banking Exam Preparation – “MULTIPLICATION” Part I

Two numbers that differ by 2-   {(a + b)/2}2 – 1

E.g.         27 x 29 = ?

27 + 29 = 56

56/2 =28

282 = (30 – 2)2 = 302 – 2 x 30 x 2 + 2= 900 – 120 + 4 = 784

784 – 1 = 783

You can get answer in less than 15 seconds by practice more and more.

Banking Exam Preparation – “MULTIPLICATION” Part I

Two numbers that differ by 3-   (Smaller number + 1)2 + (Smaller number – 1)

E.g.         26 x 29 = ?

(26 + 1)2 + (26 – 1)

272 + 25

729 +25 = 754

Two numbers that differ by 4- {(a + b)/2}2 – 4

E.g.         62 x 66 = ?

62 + 66 = 128

128/2 = 64

642 = (65 – 1)2 = 652 – 2 x 65 x 1 + 12 = 4225 – 130 + 1 = 4096

4096 – 4 = 4092

Two numbers that differ by 6- {(a + b)/2}2 – 9

E.g.         42 x 48 = ?

42 + 48 = 90

90/2 = 45

452 = 2025

2025 – 9 = 2016

Two numbers that differ by an Even number where a < b and C = (b – a)/2

{(a + b)/2}2 – c2

E.g.         51 x 59 = ?

51 + 59 = 110

110/2 = 55

552 = 3025

59 – 51 = 8

8/2 = 4

42 = 16

3025 – 16 = 3009

Two numbers that differ by an Odd number where a < b and C = [1 + (b – a)]/2

(a + c)2 – [b + (c – 1)2]

E.g.         51 x 58 = ?

C = 58 – 51 + 1/ 2 = 8/2 = 4

51 + 4 = 55

552 = 3025

58 + 32 = 67

3025 – 67 = 2958

Banking Exam Preparation – “MULTIPLICATION” Part I

You can also find

Banking Exam Preparation – “Square and Square Root”

BANKING EXAM PREPARATION – CUBE AND CUBE ROOT

Banking Exam Preparation – ADDITION and SUBTRACTION Part I

Banking Exam Preparation – ADDITION and SUBTRACTION Part II

Banking Exam Preparation – ADDITION and SUBTRACTION Part III

Banking Exam Preparation – “MULTIPLICATION” Part I

At CAKART www.cakart.in you will get everything that you need to be successful in your CA CS CMA exam – India’s best faculty video classes (online or in pen drive) most popular books of best authors (ebooks hard copies) best scanners and all exam related information and notifications.Visit www.cakart.in and chat with our counsellors any time. We are happy to help you make successful in your exams