O Level MathematicsC5.1 Units (conversion of length, area, volume, capacity).

📏 Mastering Metric Magic: Converting Length, Area, Volume & Capacity!

Edudent Academy
11 Jan 26

Whether you’re measuring fabric for a new outfit or calculating water needed to fill a fish tank, **accurate unit conversion** is essential for everyday life and O-Level exams alike. This post equips you with the must-know rules for switching between units of length, area, volume, and capacity with confidence.

Essential Conversion Ratios

  • Length: 1 km=1000 m,  1 m=100 cm,  1 cm=10 mm1\text{ km}=1000\text{ m},\;1\text{ m}=100\text{ cm},\;1\text{ cm}=10\text{ mm}
  • Area: 1 m2=10 000 cm2  (100×100)1\text{ m}^2=10\,000\text{ cm}^2 \;(100\times100)
  • Volume: 1 m3=1 000 000 cm3  (1003)1\text{ m}^3=1\,000\,000\text{ cm}^3 \;(100^3)
  • Capacity: 1 L=1000 mL1\text{ L}=1000\text{ mL} and 1 cm3=1 mL1\text{ cm}^3=1\text{ mL} (handy link between volume & capacity)

Worked Example: From Pool to Glass!

Problem: A small rectangular pool is 4.5 m4.5\text{ m} long, 2 m2\text{ m} wide and 1.2 m1.2\text{ m} deep. Find its capacity in litres. Solution: 1. **Find the volume in m3\text{m}^3:** V=4.5×2×1.2=10.8 m3V = 4.5 \times 2 \times 1.2 = 10.8\,\text{m}^3. 2. **Convert m3\text{m}^3 to cm3\text{cm}^3 (optional check):** 10.8 m3×1 000 000=10 800 000 cm310.8\,\text{m}^3 \times 1\,000\,000 = 10\,800\,000\,\text{cm}^3. 3. **Link volume to capacity:** Since 1 cm3=1 mL1\text{ cm}^3 = 1\text{ mL} and 1000 mL=1 L1000\text{ mL}=1\text{ L}, divide by 10001000.
10 800 000 cm3÷1000=10 800 L10\,800\,000\,\text{cm}^3 \div 1000 = 10\,800\,\text{L}
4. **State the answer clearly:** The pool holds **10 800 L** of water.

Practice converting **up** and **down** the metric ladder daily, and these steps will become second nature for your exam. Keep a conversion chart handy, test yourself with real-world objects, and you’ll turn unit hurdles into stepping-stones to success!