Page 46 - BUSINESS MATHEMATICS MODULE 1 (WHOLE)_revised 10.20.2020

A. MDAS
In the case where the expression does not have signs or symbols of groupings such as

parenthesis, brackets, braces, and/or an expression involving exponent, the MDAS rule is followed.

MDAS rule stands for Multiplication, Division, Addition, and Subtraction.

The rules are as follow:

(i) First, solve all Multiplication and Division from left to right.

Example 1: ⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗ ⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗
24 × 6 ÷ 2 = 144 ÷ 2 = 72
Example 2: ⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗ ⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗
24 ÷ 6 × 2 = 4 × 2 = 8
(ii) Secondly, solve all Addition and Subtraction from left to right.

Example 1: ⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗ ⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗
24 + 6 − 2 = 30 − 2 = 28
24 − 6 + 2 = 18 + 2 = 20
LESSON 3. ORDER O F O P ER A ⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗ ⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗
Example 2: TION

Examples:

1. Evaluate 3 + 6 x 9 ÷ 3 - 7 using the order of operations.

Solution:

Step 1: 3 + 6 x 9 ÷ 3 – 7 = 3 + 54 ÷ 3 - 7 Multiplication

Step 2: 3 + 54 ÷ 3 – 7 = 3 + 18 - 7 Division

Step 3: 3 + 18 – 7 = 21 - 7 Addition
Step 4: 21 – 7 = 14 Subtraction

2. Example 3: Evaluate 9 - 5 ÷ 5 x 2 + 6 using the order of operations.

Solution:

Step 1: 9 - 5 ÷ 5 x 2 + 6 = 9 - 1 x 2 + 6 Division
Step 2: 9 - 1 x 2 + 6 = 9 - 2 + 6 Multiplication

Step 3: 9 - 2 + 6 = 7 + 6 Subtraction

Step 4: 7 + 6 = 13 Addition

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