I. ‘BODMAS’ Rule : This rule depicts the correct sequence in which the operations are to be executed,
so as to find out the value of a given expression.
Here, ‘B’ stands for 'bracket' ,
'O'for ‘of’ ,
‘D’ for 'division'
‘M’ for ‘multiplication’,
‘A’ for ‘addition’ and
‘S’ for ‘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:
(1) of (2) division (3) multiplication (4)addition (5)subtraction.
II. Modulus of a real number : Modulus of a real number a is defined as
|a| = { a, if a > 0;
|a| = { -a, if a < 0;
Thus, |5| = 5 and |-5| = -(-5) = 5.
III. Virnaculum (or bar): When an expression contains Virnaculum, before applying the ‘BODMAS’ rule,
we simplify the expression under the Virnaculum.