Simplification Tricks for Bank Exams

Order of operations (BODMAS)

• Brackets → Of → Division & Multiplication → Addition & Subtraction.
• “Of” means multiply, and is done before ÷ and ×: 1/2 of 40 ÷ 4 = 20 ÷ 4 = 5.
• Division and multiplication are done left to right, as are addition and subtraction: 48 ÷ 4 × 3 = 12 × 3 = 36 (not 48 ÷ 12).

Shortcuts

• x% of y = y% of x → 8% of 50 = 50% of 8 = 4.
• a² − b² = (a + b)(a − b) → 32² − 22² = 54 × 10 = 540.
• Square of a number ending in 5: n5² = n × (n + 1), then write 25 → 65² = 6 × 7 = 42 → 4225.
• × 25 = × 100 ÷ 4 → 36 × 25 = 3600 ÷ 4 = 900. × 125 = × 1000 ÷ 8 → 48 × 125 = 48000 ÷ 8 = 6000.
• Unit-digit check: work out only the last digit of the answer first — it often eliminates three options at once.
• For “find x” questions, move the known part across first: 80% of x − 200 = 600 → 80% of x = 800 → x = 1000.

Fraction → percentage

1/2

50%

1/3

33.33%

1/4

25%

1/5

20%

1/6

16.67%

1/7

14.29%

1/8

12.5%

1/9

11.11%

1/10

10%

1/11

9.09%

1/12

8.33%

1/13

7.69%

1/14

7.14%

1/15

6.67%

1/16

6.25%

1/17

5.88%

1/18

5.56%

1/19

5.26%

1/20

5%

Squares 1–30

1²

1

2²

4

3²

9

4²

16

5²

25

6²

36

7²

49

8²

64

9²

81

10²

100

11²

121

12²

144

13²

169

14²

196

15²

225

16²

256

17²

289

18²

324

19²

361

20²

400

21²

441

22²

484

23²

529

24²

576

25²

625

26²

676

27²

729

28²

784

29²

841

30²

900

Cubes 1–20

1³

1

2³

8

3³

27

4³

64

5³

125

6³

216

7³

343

8³

512

9³

729

10³

1000

11³

1331

12³

1728

13³

2197

14³

2744

15³

3375

16³

4096

17³

4913

18³

5832

19³

6859

20³

8000