When two or more operations carried out, different answers can result depending on the order in which the operations are performed.
For example, consider the expression 16 - 10 ÷ 2
John decided to subtract first then divide. = 6 ÷ 2 = 3 |
Tina decided to divide first then subtract. = 16 - 5 = 11 |
Which answer is correct 3 or 11 ?
To avoid this confusion, we use the concept order of operations.
The word BEDMAS may help you to remember this order.
Note :
If an expression contains more than one set of brackets, evaluate the innermost brackets first.
The division line of fractions behaves like a set of brackets. This means that the numerator and denominator must each be found before doing the division
Evaluate the following numerical expression.
Example 1 :
6 x 8 - 18 ÷ (2 + 4)
Solution :
= 6 x 8 - 18 ÷ (2 + 4) = 6 x 8 - 18 ÷ 6 = 6 x 8 - 3 = 48 - 3 = 45 |
Bracket Division Multiplication Subtraction |
So, the answer is 45.
Example 2 :
10÷5+20÷(4+1)
Solution :
= 10÷5+20÷(4+1) = 10÷5+20÷5 = 2+20÷5 = 2+4 = 6 |
Bracket Division Division Addition |
Example 3 :
5 + (2x10-5) - 6
Solution :
= 5 + (2x10-5) - 6 = 5 + (20-5) - 6 = 5+15 - 6 = 20 - 6 = 14 |
Bracket, Multiplication Subtraction Addition Subtraction |
Example 4 :
18 - (15÷3+4) + 1
Solution :
= 18 - (15÷3+4) + 1 = 18 - (5+4) + 1 = 18 - 9 + 1 = 9 +1 = 10 |
Bracket, Division Bracket, Addition Subtraction Addition |
Example 5 :
(2x3-4) + (33÷11+5)
Solution :
Since we have two set of terms inside the bracket, we will simplify that first.
= (2x3-4) + (33÷11+5)
= (6-4) + (3+5)
= 2 + 8
= 10
Example 6 :
(18÷3+3) ÷ (4x4-7)
Solution :
= (18÷3+3) ÷ (4x4-7) = (6+3) ÷ (16-7) = 9 ÷ 9 = 1 |
Division, Multiplication Addition, Subtraction Division |
Example 7 :
(50÷5+6) - (8x2-4)
Solution :
= (50÷5+6) - (8x2-4)
= (10+6) - (16-4)
= 16 - 12
= 4
Example 8 :
(10x3-20) + 3(9÷3+2)
Solution :
= (10x3-20) + 3(9÷3+2)
= (30-20) + 3(3+2)
= 10+3(5)
= 10+15
= 25
Example 9 :
(7-3x2) ÷ (8÷4-1)
Solution :
= (7-3x2) ÷ (8÷4-1)
= (7-6) ÷ (2-1)
= 1 ÷ 1
= 1
Example 10 :
(5+3)x2+10 ÷ (8-3)
Solution :
= (5+3)x2+10 ÷ (8-3)
= 8x2+10÷5
= 16+10÷5
= 16+2
= 18
May 21, 24 08:51 PM
May 21, 24 08:51 AM
May 20, 24 10:45 PM