1.1.4 Combined operations on real numbers

COMBINED OPERATIONS ON REAL NUMBERS

Learning Outcomes

Apply order of operations to simplify expressions.

Solve word problems involving combined operations.

Lesson Notes

Use BODMAS:

> Brackets → Orders → Division → Multiplication → Addition → Subtraction

Worked Examples

Example 1:

Simplify: 12 − 3 × 2 + 4

= 12 − 6 + 4

= 10

Example 2:

Simplify: (8 + 2) × (6 − 4) + 5

= 10 × 2 + 5

= 20 + 5

= 25

Example 3: Real-Life Application

A shop sells 3 pens at K5 each and 2 notebooks at K12 each.

How much will a customer pay?

3 × 5 + 2 × 12 = 15 + 24 = K39

Exercise 4

Simplify:

1. (5 + 3) × 2

2. 20 ÷ 5 × 3

3. 6 × (4 + 3) − 8

4. 8 + 6 × (10 − 7)

5. A person buys 4 bottles at K10 each and 3 sodas at K8 each. Find total cost.