Units

Unit Conversions

Convert mass, time, length, temperature, and speed fluidly between different measurement systems.

Lessons included in this chapter:

• The Golden Rule: Going to a smaller unit: multiply. Going to a larger unit: divide.
• The Metric System (SI): Each step down the prefix ladder multiplies by 10, each step up divides by 10.
• Step-by-Step Dimensional Analysis: Write your units as algebraic symbols. Multiply by fractions that equal 1 until unwanted units cancel.
• Mass Conversions: 1 tonne = 1000 kg, 1 kg = 1000 g, 1 g = 1000 mg. Multiply by 1000 to go smaller; divide to go larger.
• Time Conversions: 1 week = 7 days, 1 day = 24 hours, 1 hour = 60 mins, 1 min = 60 secs. Convert step-by-step.
• Length Conversions: 1 km = 1000 m. 1 m = 100 cm = 1000 mm. For imperial: 1 inch = 2.54 cm.
• Volume Conversions: 1 Liter = 1000 milliliters. 1 Gallon = 4 quarts = 8 pints = 16 cups.
• Temperature Conversions: F = 1.8 * C + 32. C = (F - 32) * 5/9. K = C + 273.15.
• Area and Volume Units: If 1 m = 100 cm, then 1 m² = (100)² cm² = 10,000 cm², and 1 m³ = (100)³ cm³ = 1,000,000 cm³.
• Speed Conversions: To convert km/h to m/s, multiply by 5/18 (approx 0.278). To convert m/s to km/h, multiply by 3.6.
• Mental Tricks for Quick Conversions: Double Celsius and add 30 for rough Fahrenheit. Move decimal points mentally for kilo and milli.