Year 5 Maths: Converting Units of Lengths

Introduction to Lengths

Hello, Year 5! Today, we are going to learn about converting units of lengths. This means changing a measurement from one unit to another, like from centimetres to metres. Length is how long something is, and we can measure it in different ways!

Common Units of Length

Here are some common units of length you might know:

• Millimetres (mm): Very small measurements. There are 1,000 millimetres in a metre.
• Centimetres (cm): A little bigger than millimetres. There are 100 centimetres in a metre.
• Metres (m): A standard measurement for length.
• Kilometres (km): This is used for longer distances. There are 1,000 metres in a kilometre.

Key Rules for Converting Lengths

1. To convert from a smaller unit to a larger unit, you divide.
   • Example: Convert 200 cm to m.
     • Since there are 100 cm in 1 m, we divide 200 by 100.
     • $$200 \div 100 = 2 \text{ m}$$
2. To convert from a larger unit to a smaller unit, you multiply.
   • Example: Convert 3 m to cm.
     • Since there are 100 cm in 1 m, we multiply 3 by 100.
     • $$3 \times 100 = 300 \text{ cm}$$

Tips and Tricks

• Remember the Relationships:
  • 1 km = 1,000 m
  • 1 m = 100 cm
  • 1 cm = 10 mm
• Use a Conversion Chart: Having a simple chart can help you remember these conversions easily.
• Practice with Real-Life Examples: Think about measuring objects around your house. How long is your pencil in cm? How long is your room in m?

Examples

1. Convert 150 mm to cm.
   • Since there are 10 mm in 1 cm:
   • $$150 \div 10 = 15 \text{ cm}$$
2. Convert 5 km to m.
   • Since there are 1,000 m in 1 km:
   • $$5 \times 1,000 = 5,000 \text{ m}$$

Practice Questions

Easy Level Questions

1. Convert 120 cm to m.
2. Convert 3 m to cm.
3. Convert 250 mm to cm.
4. Convert 1 km to m.
5. Convert 50 cm to mm.
6. Convert 2.5 m to cm.
7. Convert 500 mm to cm.
8. Convert 10 m to mm.
9. Convert 4 km to m.
10. Convert 300 cm to m.
11. Convert 2 cm to mm.
12. Convert 1000 mm to m.
13. Convert 6 m to cm.
14. Convert 25 mm to cm.
15. Convert 7 km to m.
16. Convert 15 cm to mm.
17. Convert 8 m to mm.
18. Convert 0.5 km to m.
19. Convert 90 cm to m.
20. Convert 12 mm to cm.

Medium Level Questions

1. Convert 1.5 m to cm.
2. Convert 7 km to cm.
3. Convert 600 mm to cm.
4. Convert 4 m to km.
5. Convert 3.2 km to m.
6. Convert 90 mm to cm.
7. Convert 15 m to cm.
8. Convert 2.2 km to m.
9. Convert 400 cm to mm.
10. Convert 5.5 m to cm.
11. Convert 2 km to mm.
12. Convert 80 cm to m.
13. Convert 3000 mm to m.
14. Convert 9 m to km.
15. Convert 250 cm to m.
16. Convert 0.75 km to m.
17. Convert 45 mm to cm.
18. Convert 20 m to cm.
19. Convert 3.5 km to mm.
20. Convert 2.5 m to km.

Hard Level Questions

1. Convert 7.8 m to cm.
2. Convert 1.2 km to cm.
3. Convert 3.3 km to m.
4. Convert 450 mm to m.
5. Convert 5.75 m to cm.
6. Convert 9.9 km to m.
7. Convert 650 cm to mm.
8. Convert 4.2 km to cm.
9. Convert 0.25 km to m.
10. Convert 1500 mm to km.
11. Convert 2.8 m to km.
12. Convert 3.6 km to cm.
13. Convert 700 mm to cm.
14. Convert 20.5 m to cm.
15. Convert 5 km to mm.
16. Convert 0.9 km to m.
17. Convert 300 cm to mm.
18. Convert 8.4 m to km.
19. Convert 900 mm to m.
20. Convert 1.1 km to cm.

Answers and Explanations

Easy Level Answers

1. 1.2 m
2. 300 cm
3. 25 cm
4. 1,000 m
5. 500 mm
6. 250 cm
7. 50 cm
8. 10,000 mm
9. 4,000 m
10. 3 m
11. 20 mm
12. 1 m
13. 600 cm
14. 2.5 cm
15. 7,000 m
16. 150 mm
17. 8,000 mm
18. 500 m
19. 0.9 m
20. 1.2 cm

Medium Level Answers

1. 150 cm
2. 700,000 cm
3. 60 cm
4. 0.004 km
5. 3,200 m
6. 9 cm
7. 1,500 cm
8. 2,200 m
9. 4,000 mm
10. 550 cm
11. 2,000 mm
12. 0.8 m
13. 3 m
14. 2.5 m
15. 750 cm
16. 750 m
17. 4.5 cm
18. 2,000 cm
19. 35,000 mm
20. 250 m

Hard Level Answers

1. 780 cm
2. 120,000 cm
3. 3,300 m
4. 0.45 m
5. 575 cm
6. 9,900 m
7. 6,500 mm
8. 420,000 cm
9. 250 m
10. 1.5 km
11. 0.0028 km
12. 360,000 cm
13. 65 cm
14. 2,050 cm
15. 5,000 m
16. 900 m
17. 3,000 mm
18. 0.084 km
19. 0.9 m
20. 110 cm

Now you have everything you need to understand converting units of lengths! Remember to practice these conversions, and soon you’ll be a pro at it! Happy learning!