Conversion Between Metric and Customary Units

Introduction

• Presenter: Maria from Math Mammoths
• Focus: Converting between metric and customary measuring units
• Note: This is often a difficult topic, so it will be covered slowly.

Key Conversion Factors

• Length
  • 1 inch = 2.54 centimeters
  • 1 foot into meters (not specified, but likely ~0.3048)
  • 1 mile into kilometers (not specified, but likely ~1.60934)
• Volume
  • 1 quart = 0.946 liters
• Mass/Weight
  • 1 ounce = 28.35 grams
  • 1 kilogram = 2.2 pounds

Conversion Process

Problem 1: Meters to Feet

• Example: Convert 4.82 meters to feet
• Conversion Factor: 1 foot = (~0.3048) meters
• Process:
  • Identify larger unit: Meters
  • Result in smaller unit (feet) should be larger
  • Action: Divide by conversion factor
  • Result: Approximately 15.8 feet

Problem 2: Kilometers to Miles

• Example: Convert 17 kilometers to miles
• Conversion Factor: 1 mile = 1.60934 kilometers
• Process:
  • Identify larger unit: Miles
  • Result in smaller unit (miles) should be smaller
  • Action: Divide by conversion factor
  • Result: Approximately 10.56 miles

Problem 3: Kilograms to Pounds

• Example: Convert kilograms to pounds
• Conversion Factor: 1 kilogram = 2.2 pounds
• Process:
  • Identify larger unit: Kilograms
  • Result in smaller unit (pounds) should be larger
  • Action: Multiply by conversion factor

Problem 4: Gallons/Quarts to Liters

• Example: Convert 6 gallons 3 quarts to liters
• Conversion Factors:
  • 1 gallon = 4 quarts
  • 1 quart = 0.946 liters
• Process:
  • Convert gallons to quarts first
  • Total quarts = 27 quarts
  • Action: Multiply by conversion factor
  • Result: Approximately 25.54 liters

Problem 5: Pounds and Ounces to Kilograms

• Example: Convert 3 pounds 15 ounces into kilograms
• Conversion Factors:
  • 1 pound = 16 ounces
  • 1 ounce = 28.35 grams
• Process:
  • Convert pounds to ounces: 3 pounds = 48 ounces
  • Total = 63 ounces
  • Action: Multiply by grams conversion factor
  • Convert grams to kilograms
  • Result: Approximately 1.786 kilograms

Problem 6: Milliliters to Fluid Ounces

• Conversion Factors Needed:
  • 1 quart = 946 milliliters
  • 1 quart = 32 fluid ounces
• Process:
  • Derive: 1 fluid ounce = (946 / 32) milliliters
  • 1 fluid ounce ≈ 29.5625 milliliters
  • Action: Divide to convert to fluid ounces
  • Result: Approximately 11.9 fluid ounces

Conclusion

• Critical thinking needed to determine whether to multiply or divide
• Understanding relative sizes of units is crucial for accurate conversion