Chapter 5.5 (Mathematics 5)

Combined operations involving addition, subtraction, multiplication and division

Combined operations involving addition, subtraction, multiplication and division

Work out 8 + 6 × 2. In pairs:

  1. Multiply 6 by 2.
    6 × 2 = 
  2. Add 8 to the product.
    8 +  = 
  3. Discuss the result with other groups.
  4. Work out the following and drag the results. Discuss in your groups.
  • 20
  • 11
  • 4
  • 5
  • 6 × 2 + 8
  • 8 + 6 ÷ 2
  • 6 × 2 – 8
  • 8 – 6 ÷ 2

Example 6

Work out:

a) 5 + 12 ÷ 3

Step 1:

12 ÷ 3 = 4

Step 2:

5 + 4 = 9

5 + 12 ÷ 3 = 9

b) 19 – 3 × 5

Step 1:

3 × 5 = 15

Step 2:

19 – 15 = 4

19 – 3 × 5 = 4

c) 24 ÷ 6 × 7

Step 1:

24 ÷ 6 = 4

Step 2:

4 × 7 = 28

24 ÷ 6 × 7 = 28

d) 10 + 12 ÷ 2 – 4

Step 1:

12 ÷ 2 = 6

Step 2:

10 + 6 = 16

10 – 4 = 12

Exercise E

  1. 24 + 9 × 3 = 
  2. 18 + 15 ÷ 5 = 
  3. 10 – 8 ÷ 4 = 
  1. 16 + 14 × 2 = 
  2. 28 – 24 ÷ 6 = 
  3. 15 ÷ 3 + 13 = 
  1. 20 × 2 – 32 = 
  2. 30 ÷ 5 – 3 = 
  3. 72 ÷ 9 + 200 = 
  1. 48 ÷ 6 × 15 = 
  2. 9 × 36 ÷ 4 = 
  3. 65 ÷ 13 × 100 = 

E5

Work out:

  1. 54 × 12 ÷ 4 + 8
  2. 32 – 27 ÷ 9 + 5
  3. 100 × 28 ÷ 7 + 600
  4. 120 × 30 ÷ 6 – 250