Multiplying decimals (focused practice) worksheet

Part A: Working out and filling in

1. 1. 0.17 × 0.6 = 0.102

   0.17 × 0.6: multiply as whole numbers, 17 × 6 = 102; 0.17 has two places and 0.6 has one place, 2 + 1 = 3 in all, so put the point back three places into 102 → 0.102

2. 2. 0.5 × 6 = 3

   0.5 × 6: multiply as whole numbers, 5 × 6 = 30; 0.5 has one place, so put the point back one place into 30 → 3.0 = 3

3. 3. 0.6 × 0.5 = 0.3

   0.6 × 0.5: multiply as whole numbers, 6 × 5 = 30; 0.6 has one place and 0.5 has one place, 1 + 1 = 2 in all, so put the point back two places into 30 → 0.30 = 0.3

4. 4. 0.17 × 0.8 = 0.136

   0.17 × 0.8: multiply as whole numbers, 17 × 8 = 136; 0.17 has two places and 0.8 has one place, 2 + 1 = 3 in all, so put the point back three places into 136 → 0.136

5. 5. 7 × 0.9 = 6.3

   7 × 0.9: multiply as whole numbers, 7 × 9 = 63; 0.9 has one place, so put the point back one place into 63 → 6.3

6. 6. 1.5 × 0.3 = 0.45

   1.5 × 0.3: multiply as whole numbers, 15 × 3 = 45; 1.5 has one place and 0.3 has one place, 1 + 1 = 2 in all, so put the point back two places into 45 → 0.45

7. 7. 2 × 1.9 = 3.8

   2 × 1.9: multiply as whole numbers, 2 × 19 = 38; 1.9 has one place, so put the point back one place into 38 → 3.8

8. 8. 0.6 × 4 = 2.4

   0.6 × 4: multiply as whole numbers, 6 × 4 = 24; 0.6 has one place, so put the point back one place into 24 → 2.4

9. 9. 0.8 × 5 = 4

   0.8 × 5: multiply as whole numbers, 8 × 5 = 40; 0.8 has one place, so put the point back one place into 40 → 4.0 = 4

10. 10. 0.15 × 4 = 0.6

    0.15 × 4: multiply as whole numbers, 15 × 4 = 60; 0.15 has two places, so put the point back two places into 60 → 0.60 = 0.6

11. 11. 0.13 × 2 = 0.26

    0.13 × 2: multiply as whole numbers, 13 × 2 = 26; 0.13 has two places, so put the point back two places into 26 → 0.26

12. 12. 4 × 0.8 = 3.2

    4 × 0.8: multiply as whole numbers, 4 × 8 = 32; 0.8 has one place, so put the point back one place into 32 → 3.2

Part B: Word problems

Marking: 2 for the working, 1 for the answer, 1 for the sentence.

1. 13. One lap of a jogging trail in the park is 1.4 km. May runs 5 laps. How many kilometres does she run? (Answer: 7 km)

   1.4 × 5 = 7

2. 14. One lap of a jogging trail in the park is 3.7 km. Ka-lok runs 2 laps. How many kilometres does he run? (Answer: 7.4 km)

   3.7 × 2 = 7.4

3. 15. Apples cost $16.5 a kilogram. Mum buys 2 kg. How many dollars must she pay? (Answer: 33 dollars)

   16.5 × 2 = 33

4. 16. Each bottle of drink weighs 0.4 kg. A crate holds 5 bottles, and the empty crate weighs 0.6 kg. How many kilograms does the full crate weigh? (Answer: 2.6 kg)

   0.4 × 5 + 0.6 = 2.6

5. 17. Each bottle of drink weighs 0.35 kg. A crate holds 4 bottles, and the empty crate weighs 0.7 kg. How many kilograms does the full crate weigh? (Answer: 2.1 kg)

   0.35 × 4 + 0.7 = 2.1

6. 18. Apples cost $18.5 a kilogram. Mum buys 3 kg. How many dollars must she pay? (Answer: 55.5 dollars)

   18.5 × 3 = 55.5