Simplification & Approximation
GETTING STARTED
☛ BODMAS rule:
The long mathematical expressions are always solved using BODMAS rule.
It gives the sequence in which expressions are solved.
B – Bracket
O – Of
D-Division
M-Multiplication
A-Addition
S-Subtraction
☛ First the brackets are solved. Within brackets also there is an order to solve – (), then {} and then [ ].
☛ After brackets, Division operation is to be carried out followed by Multiplication.
☛ After multiplication, addition and subtraction are carried out.
☛ Virnaculum:
Some questions may have a bar over a few terms indicating that they are to be solved even before starting off with brackets
☛ Modulus of a number:
This expression always returns a non-negative value irrespective of the input.
Y= f (x) =|x|
Eg. Let x = 50
Y= |50| = 50
Let x = -50
Y = |-50| = 50
Approximation:
☛It helps in quickening the process of arriving at an answer. It is one of the most important topics to be continuously practiced for MCQ type exams.
☛ Approximation helps in eliminating incorrect answer choices quickly.
☛The best way to approximate is to reduce the numbers to its nearest integer which can be easily used for calculation.
Let us consider an example:

A) 302
B) 502
C)202
D)102
Soln:
Approximating, we get,


Solving Further,
=(60 + 140 -230 +230)/2
=100
Of the given options, the alternatives are too apart the closest number is 102.
Therefore D is the right answer.