Converting and Calculating Units of Length

Metric units of length are used to measure distances and sizes accurately. The most common metric units of length are:

• Millimeters (mm): Smallest unit here, used for tiny objects.
  • 1 mm is about the thickness of a credit card.
• Centimeters (cm): Common for everyday objects.
  • 1 cm is about the width of a fingernail.
• Meters (m): Used for measuring rooms, furniture, or height.
  • 1 m is about the height of a chair.
• Kilometers (km): Used for long distances.
  • 1 km is about the distance between two bus stops.

You need to remember these key conversions between units of lengths:

• 1 mm = 0.1 cm
• 1 cm = 10 mm
• 1 m = 100 cm
• 1 km = 1000 m

🌟 Example 1: Converting 47 meters to centimeters

1. Meters to centimeters → Multiply by 100 (since 1 m = 100 cm).
2. $47 \times 100 = 4700$
3. So, 47 meters = 4700 centimeters ✅

🌟 Example 2: Converting 5020 meters to kilometers

1. Meters to kilometers → Divide by 1,000 (since 1 km = 1000 m).
2. $5020 \div 1000 = 5.020$
3. So, 5020 meters = 5.02 kilometers ✅

When performing calculations with different length units, convert to the same unit first.

🌟 Example 1: Adding 1.75 m and 40 cm

1. Convert 40 cm to m: $40 \text{ cm} = 0.4 \text{ m}$
2. Add the values in meters: $1.75 \text{ m} + 0.4 \text{ m} = 2.15 \text{ m}$
3. Final Answer: 2.15 m ✅ 

🌟 Example 2: Subtracting 40 cm from 1.75 m

1. Convert 1.75 m to cm: $1.75 \text{ m} = 175 \text{ cm}$
2. Subtract the values in cm: $175 \text{ cm} – 40 \text{ cm} = 135 \text{ cm}$
3. (Optional) Convert back to m: $135 \text{ cm} = 1.35 \text{ m}$
4. Final Answer: 1.35 m ✅