Every metric conversion is a multiplication or division by a power of 10 — the only real skill is remembering which direction to go.
Study Zone is free for our students — you just need to log in with your WhatsApp number first.
Log in with WhatsApp →The first two chapters of every book are free once you're logged in. To open this one, request an unlock and we'll get back to you on WhatsApp.
Length, mass and capacity all use the same pattern of prefixes — kilo, base unit, and milli.
📊 The three metric ladders
| Length | Mass | Capacity |
|---|---|---|
| 1 km = 1000 m | 1 kg = 1000 g | 1 L = 1000 mL |
| 1 m = 100 cm | 1 g = 1000 mg | — |
| 1 cm = 10 mm | — | — |
Direction rule: converting from a BIGGER unit to a SMALLER unit means multiplying; converting from smaller to bigger means dividing. 5 km → m: multiply by 1000 = 5000 m. 2500 m → km: divide by 1000 = 2.5 km.
Time does not follow the base-10 pattern — it is built on 60s and 24s instead, which is exactly why it trips people up.
📊 Time units
| Conversion | Value |
|---|---|
| 1 hour | 60 minutes |
| 1 minute | 60 seconds |
| 1 day | 24 hours |
| 1 hour | 3600 seconds |
Trap: "1.5 hours" is NOT "1 hour 5 minutes" — it is 1 hour plus 0.5×60=30 minutes, so 1 hour 30 minutes.
Celsius and Fahrenheit do not start at the same zero point, which is why the conversion needs both a multiplication AND an addition.
🏆 The temperature formulas
Celsius to Fahrenheit: F = (C × 9/5) + 32.
Fahrenheit to Celsius: C = (F − 32) × 5/9.
Two fixed points to remember: 0°C = 32°F (freezing), 100°C = 212°F (boiling).
Worked example: normal human body temperature, 98.6°F, converts to (98.6−32)×5/9 = 37°C.
12 questions on metric conversions, time and temperature.
