Year 7 Maths: Convert Between Metric and Imperial Units

Introduction

Today, we’re going to learn how to convert between metric and imperial units. This is an important skill because it helps us understand measurements used in different countries.

What are Metric and Imperial Units?

• Metric Units: These include millimeters (mm), centimeters (cm), meters (m), and kilograms (kg). They are based on the number 10, which makes them easier to use and convert.
• Imperial Units: These include inches (in), feet (ft), yards (yd), and pounds (lb). They can be a bit tricky because they don’t follow the same base-10 system.

Key Rules for Conversion

Length Conversions

• Inches to Centimeters: To convert inches to centimeters, multiply by 2.54.Example: $$5 \text{ in} \times 2.54 = 12.7 \text{ cm}$$
• Centimeters to Inches: To convert centimeters to inches, divide by 2.54.Example: $$10 \text{ cm} \div 2.54 \approx 3.94 \text{ in}$$
• Feet to Meters: To convert feet to meters, multiply by 0.3048.Example: $$6 \text{ ft} \times 0.3048 = 1.83 \text{ m}$$
• Meters to Feet: To convert meters to feet, multiply by 3.281.Example: $$2 \text{ m} \times 3.281 \approx 6.56 \text{ ft}$$

Weight Conversions

• Pounds to Kilograms: To convert pounds to kilograms, multiply by 0.4536.Example: $$10 \text{ lb} \times 0.4536 = 4.54 \text{ kg}$$
• Kilograms to Pounds: To convert kilograms to pounds, multiply by 2.2046.Example: $$5 \text{ kg} \times 2.2046 \approx 11.02 \text{ lb}$$

Volume Conversions

• Gallons to Litres: To convert gallons to litres, multiply by 4.546.Example: $$1 \text{ gallon} \times 4.546 \approx 4.54 \text{ L}$$
• Litres to Gallons: To convert litres to gallons, divide by 4.546.Example: $$10 \text{ L} \div 4.546 \approx 2.20 \text{ gallons}$$

Tips and Tricks

1. Use Reference Charts: Keep a chart handy for quick conversions.
2. Practice: The more you practice, the easier it gets!
3. Estimate: If you’re unsure, make an estimate to check if your answer seems reasonable.
4. Memorise Key Conversions: Try to remember some common conversions, like 1 inch is about 2.5 cm.

Questions

Easy Level Questions

1. Convert 10 inches to centimeters.
2. How many centimeters are in 20 inches?
3. Convert 5 pounds to kilograms.
4. How many kilograms are in 10 pounds?
5. Convert 1 foot to meters.
6. How many meters are in 3 feet?
7. Convert 2 gallons to litres.
8. How many litres are in 4 gallons?
9. Convert 30 centimeters to inches.
10. How many inches are in 15 centimeters?
11. Convert 1000 grams to kilograms.
12. How many kilograms are in 500 grams?
13. Convert 2.5 feet to inches.
14. How many inches are in 6.5 feet?
15. Convert 5 litres to gallons.
16. How many gallons are in 8 litres?
17. Convert 1 metre to feet.
18. How many feet are in 2.5 metres?
19. Convert 10 ounces to grams.
20. How many grams are in 15 ounces?

Medium Level Questions

1. Convert 15 inches to centimeters.
2. How many centimeters are in 50 inches?
3. Convert 12 pounds to kilograms.
4. How many kilograms are in 25 pounds?
5. Convert 6 feet to meters.
6. How many meters are in 10 feet?
7. Convert 3 gallons to litres.
8. How many litres are in 7 gallons?
9. Convert 45 centimeters to inches.
10. How many inches are in 90 centimeters?
11. Convert 1500 grams to kilograms.
12. How many kilograms are in 2500 grams?
13. Convert 5.5 feet to inches.
14. How many inches are in 8.5 feet?
15. Convert 10 litres to gallons.
16. How many gallons are in 20 litres?
17. Convert 2.5 metres to feet.
18. How many feet are in 1.5 metres?
19. Convert 20 ounces to grams.
20. How many grams are in 30 ounces?

Hard Level Questions

1. Convert 37 inches to centimeters.
2. How many centimeters are in 120 inches?
3. Convert 24 pounds to kilograms.
4. How many kilograms are in 60 pounds?
5. Convert 10 feet to meters.
6. How many meters are in 15 feet?
7. Convert 5 gallons to litres.
8. How many litres are in 15 gallons?
9. Convert 100 centimeters to inches.
10. How many inches are in 250 centimeters?
11. Convert 2500 grams to kilograms.
12. How many kilograms are in 3500 grams?
13. Convert 9.5 feet to inches.
14. How many inches are in 12.5 feet?
15. Convert 15 litres to gallons.
16. How many gallons are in 25 litres?
17. Convert 3.2 metres to feet.
18. How many feet are in 4.5 metres?
19. Convert 70 ounces to grams.
20. How many grams are in 90 ounces?

Answers

Easy Level Answers

1. 25.4 cm
2. 50.8 cm
3. 4.54 kg
4. 4.54 kg
5. 0.3048 m
6. 0.9144 m
7. 9.09 L
8. 18.93 L
9. 11.81 in
10. 5.91 in
11. 1 kg
12. 0.5 kg
13. 30 in
14. 78 in
15. 1.32 gallons
16. 2.11 gallons
17. 3.28 ft
18. 8.2 ft
19. 283.5 g
20. 425.2 g

Medium Level Answers

1. 38.1 cm
2. 127 cm
3. 5.44 kg
4. 11.34 kg
5. 1.83 m
6. 3.05 m
7. 11.36 L
8. 26.50 L
9. 17.72 in
10. 35.43 in
11. 1.5 kg
12. 2.5 kg
13. 66 in
14. 102 in
15. 2.64 gallons
16. 5.28 gallons
17. 8.2 ft
18. 4.92 ft
19. 567 g
20. 850 g

Hard Level Answers

1. 93.98 cm
2. 304.8 cm
3. 10.89 kg
4. 27.22 kg
5. 3.05 m
6. 4.57 m
7. 18.93 L
8. 56.78 L
9. 39.37 in
10. 98.43 in
11. 2.5 kg
12. 3.5 kg
13. 114 in
14. 150 in
15. 3.96 gallons
16. 6.60 gallons
17. 10.50 ft
18. 14.76 ft
19. 1984 g
20. 2556 g

Feel free to try these questions to test your understanding of converting between metric and imperial units! Happy learning!