# Arithmetic Aptitude :: Simplification

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## Simplification Important Formulas

1. 'BODMAS' Rule:

This rule depicts the correct sequence in which the operations are to be executed, so as to find out the value of given expression.

B - Bracket,

O - of,

D - Division,

M - Multiplication,

S - Subtraction

Thus, in simplifying an expression, first of all the brackets must be removed, strictly in the order ( ), { } and [ ].
After removing the brackets, we must use the following operations strictly in the order:

(i) of

(ii) Division

(iii) Multiplication

(v) Subtraction.

2. Modulus of a Real Number:

Modulus of a real number a is defined as

$$\left| x \right| = \begin{cases} \ \ \ a, \ if \ a > 0 \\ -a, \ if \ a < 0 \\ \end{cases}$$

Ex. |5| = 5 and |-5| = -(-5) = 5.

3. Virnaculum (or Bar):

When an expression contains Virnaculum, before applying the 'BODMAS' rule, we simplify the expression under the Virnaculum.