In this section, the following topics are discussed with examples

  • BODMAS Rule
  • Tips to crack approximation
  • Examples

BODMAS Rule

It defines the correct sequence in which operations are to be performed in a given mathematical expression to find the correct value. This means that to simplify an expression, the following order must be followed –

B O D M A S

B = Bracket,

O = Order (Powers, Square Roots, etc.)

D = Division

M = Multiplication

A = Addition

S = Subtraction

Example 1:

Solve 12 + 22 ÷ 11 × (18 ÷ 3)^2 – 10

Sol:

= 12 + 22 ÷ 11 × 6^2 – 10 (Brackets first)

= 12 + 22 ÷ 11 × 36 – 10 (Exponents)

= 12 + 2 × 36 – 10 = 12 + 72 – 10 (Division and multiplication, left to right)

= 84 – 10 = 74 (Addition and Subtraction, left to right)

Tips to Crack Approximation :

Conversion of decimal numbers to nearest number. To solve such questions, first convert the decimal to nearest value. Then simplify the given equation using the new values that you have obtained.


The ability to simplify seems to eliminate the unnecessary so that the necessary may speak.

Hans Hoffman

Example 2 :

Solve 4433.764 – 2211.993 – 1133.667 + 3377.442

Sol:

4433.764 = 4434

2211.993 = 2212

1133.667 = 1134

3377.442 = 3377

Now simplify, 4434 – 2212 – 1134 + 3377 = 4466.


Example 3:

(38/85) x (255/114) ÷ (19/5) + (14/19) = ?

Soln:

[(38/85)*(255/114)]/ (19/5) + (14/19)  

5/19+14/19 = 1


Example 4:

Which of the following can be used to compute (34*4 ½)?

a) (30*4)+(4*4 ½)

b)(34*40)+(34*½)

c)(30*4 ½)+(4*4)

d)(34*½)+(30*4)+(4*4)

Soln: 

(34*4 ½) = 34 * (4+½) = (34*4)+(34*½)

= (30*4)+(4*4)+(34*½)