Length, perimeter, mass and capacity – Year 3 maths worksheet answers to download as PDF

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1. Answer to Question 1

   1. 3 × 100 = 300 cm.
   2. 400 + 25 = 425 cm.
   3. 250 cm = 200 cm + 50 cm = 2 m 50 cm.
   4. 50 ÷ 10 = 5 cm.
   5. 3 × 1000 = 3000 m.

2. Answer to Question 2

   1. The strip starts at 0 and ends at the 9 cm mark, so it is 9 cm long.
   2. Each centimetre is 10 millimetres, so 9 cm = 9 × 10 = 90 mm.
   3. 5 cm longer means add: 9 + 5 = 14 cm.
   4. Find the difference between 15 cm and 9 cm: 15 − 9 = 6 cm shorter.

3. Answer to Question 3

   1. 8 + 3 + 8 + 3 = 22 cm.
   2. 12 + 5 + 12 + 5 = 34 cm.
   3. 20 + 9 + 20 + 9 = 58 m.
   4. 7 + 7 + 7 + 7 = 28 cm.

4. Answer to Question 4

   1. 2 × 1000 = 2000 g.
   2. 3500 = 3000 + 500, so 3 kg 500 g.
   3. 4 × 1000 = 4000 ml.
   4. 1500 = 1000 + 500, so 1 l 500 ml.
   5. 1000 ÷ 2 = 500 ml.

5. Answer to Question 5

   1. The labelled marks go 200, 400, 600, 800, 1000 ml. The water level is level with the 600 mark, so there is 600 ml.
   2. 1 litre is 1000 ml. Count on from 600 to 1000: 400 ml more is needed.
   3. Share 600 ml equally into two cups: 600 ÷ 2 = 300 ml in each cup.

6. Answer to Question 6

   1. m: a pitch is about 100 metres long.
   2. kg: a bag of rice is about 1 kilogram.
   3. ml: a cup holds about 200 millilitres.
   4. km: it is a long road journey.
   5. g: a feather is very light.

7. Answer to Question 7

   1. 9 + 4 + 9 + 4 = 26 m.
   2. 26 × £3. 20 × 3 = 60 and 6 × 3 = 18. 60 + 18 = £78.
   3. 26 − 2 = 24 m.
   4. New length 12 m. 12 + 4 + 12 + 4 = 32 m.

8. Answer to Question 8

   1. 250 + 175 + 125 = 550 g.
   2. 1000 − 250 = 750 g.
   3. 2 × 400 = 800 ml. That is 800 ml, less than 1 litre.
   4. 1000 − 800 = 200 ml.

9. Answer to Question 9

   1. Ben jumped 2 m 15 cm = 215 cm. Aisha 190 cm and Dev 2 m 5 cm = 205 cm. Ben jumped the furthest.
   2. 215 − 190 = 25 cm.
   3. 205 + 12 = 217 cm = 2 m 17 cm.
   4. 215 cm, 205 cm, 190 cm: Ben, Dev, Aisha.

10. Answer to Question 10

    1. Add the grapes and strawberries: 750 g + 500 g = 1250 g. 1000 g is 1 kg, so this is 1 kg 250 g.
    2. Change the apples into grams: 2 kg = 2000 g. Then 2000 + 1250 = 3250 g.
    3. 3250 g has 3 whole thousands of grams and 250 g more: 3 kg 250 g.
    4. 4 kg is 4000 g. Count on from 3250 to 4000: 750 g. He can buy 750 g more.

11. Answer to Question 11

    1. 8 × 5 = 40 l.
    2. 60 − 40 = 20 l.
    3. 20 ÷ 5 = 4 buckets.
    4. 1 l = 4 cups, so 5 l = 5 × 4 = 20 cups.

12. Answer to Question 12

    1. Perimeter means the distance all round the edge. Add all four sides: 50 + 30 + 50 + 30 = 160 m.
    2. 3 laps is 3 × 160 m. 3 × 100 = 300 and 3 × 60 = 180, so 300 + 180 = 480 m.
    3. 1 km is 1000 m. Count on from 480 to 1000: 20 to 500, then 500 more. 20 + 500 = 520 m short.
    4. A square has 4 equal sides of 4 m: 4 + 4 + 4 + 4 = 16 m.

13. Answer to Question 13

    1. 2000 + 500 = 2500 g.
    2. 1000 + 1000 + 500 = 2500 g.
    3. 2500 − 750 = 1750 g = 1 kg 750 g.
    4. Less, because 1750 g is less than 2000 g.

14. Answer to Question 14

    1. The tank holds 50 l and already has 18 l. Count on from 18 to 50: 2 to 20, then 30 more. Dad puts in 32 l.
    2. Each litre costs £2: 32 × £2 = £64 (double 32).
    3. After filling, the tank is full with 50 l. He uses 15 l: 50 − 15 = 35 l left.
    4. 1 litre is 1000 ml, so 35 l = 35 × 1000 = 35 000 ml.

15. Answer to Question 15

    1. 45 + 30 + 45 + 30 = 150 cm.
    2. 1 m 50 cm.
    3. 200 − 150 = 50 cm.
    4. 55 + 40 + 55 + 40 = 190 cm. 190 is less than 200, so yes, 2 m is enough, with 10 cm to spare.

16. Answer to Question 16

    1. 5 × 800 = 4000 g = 4 kg.
    2. 6 × 400 = 2400 g = 2 kg 400 g.
    3. 4000 + 2400 = 6400 g = 6 kg 400 g.
    4. 6 kg 400 g is more than 5 kg, so he needs 2 boxes.

17. Answer to Question 17

    1. 100 + 40 + 100 + 40 = 280 m.
    2. 5 × 280 = 1400 m, which is 1 km 400 m.
    3. 4 × 280 = 1120 m. 1120 − 1000 = 120 m.
    4. 2 × 280 = 560 m. Half a km is 500 m. Yes, 560 > 500.

18. Answer to Question 18

    1. 3 + 5 + 2 = 10 l.
    2. 40 − 10 = 30 l.
    3. 40 ÷ 10 = 4 times.
    4. 5 l = 5000 ml. 5000 ÷ 250 = 20 plants.

19. Answer to Question 19

    1. 3 m = 300 cm. Wrong; he multiplied by 10 instead of 100.
    2. 2000 + 400 = 2400. Right.
    3. Tom multiplied 6 × 4 (the area). The perimeter is 6 + 4 + 6 + 4 = 20 cm. Wrong.
    4. 1000 + 500 = 1500. Right.

20. Answer to Question 20

    1. Half the perimeter is 15 cm, which is the length plus the width. If the length is 5 cm longer, the width is (15 − 5) ÷ 2 = 5 and the length is 10. So the width is 5 cm and the length is 10 cm.
    2. 10 + 5 + 10 + 5 = 30 cm.
    3. Many answers work, for example 12 cm by 3 cm: 12 + 3 + 12 + 3 = 30. Also 8 cm by 7 cm or 14 cm by 1 cm.