Mathematics
Grade 4
15 min
Convert between metric and customary units
Convert between metric and customary units
Tutorial Preview
1
Introduction & Learning Objectives
Learning Objectives
Identify which units belong to the metric system and which belong to the customary system.
Recall common conversion factors between metric and customary units (e.g., 1 inch ≈ 2.54 cm).
Convert measurements of length from customary to metric units (inches to centimeters, feet to meters).
Convert measurements of volume from metric to customary units (liters to quarts).
Convert measurements of mass from customary to metric units (pounds to kilograms).
Use multiplication and division with decimals to solve one-step conversion problems.
Compare two measurements given in different systems (e.g., which is longer, 1 meter or 3 feet?).
Have you ever wondered why your soda bottle is measured in liters but your milk is in gallons? 🥤 Let's find out why and ho...
2
Key Concepts & Vocabulary
TermDefinitionExample
Customary SystemThe measurement system most commonly used in the United States.Inches, feet, yards, miles (for length); ounces, pounds (for weight); cups, quarts, gallons (for volume).
Metric SystemA measurement system based on the number 10, used by most countries around the world.Centimeters, meters, kilometers (for length); grams, kilograms (for mass); milliliters, liters (for volume).
ConversionThe process of changing a measurement from one unit to another without changing its actual size or value.Changing 1 foot into 12 inches is a conversion.
Conversion FactorA number used to multiply or divide a quantity when converting from one unit to another.The conversion factor to change inches to centimeters is about 2.54, because 1 inch ≈ 2.54 cm.
LengthThe measurement...
3
Core Formulas
Inches to Centimeters
\text{Number of inches} \times 2.54 \approx \text{Number of centimeters}
To convert a length from inches to centimeters, you multiply the number of inches by the conversion factor 2.54.
Pounds to Kilograms
\text{Number of pounds} \div 2.2 \approx \text{Number of kilograms}
To convert a weight from pounds to kilograms, you divide the number of pounds by the conversion factor 2.2.
Liters to Quarts
\text{Number of liters} \times 1.06 \approx \text{Number of quarts}
To convert a volume from liters to quarts, you multiply the number of liters by the conversion factor 1.06.
4 more steps in this tutorial
Sign up free to access the complete tutorial with worked examples and practice.
Sign Up Free to ContinueSample Practice Questions
Challenging
A garden snake is 20 inches long. A fence is 50 centimeters long. Which is longer, and by approximately how much? (Use 1 inch ≈ 2.54 cm)
A.The snake is longer by 0.8 cm.
B.The fence is longer by 30 cm.
C.The snake is longer by 29.46 cm.
D.The fence is longer by 24.6 cm.
Challenging
A recipe from France requires 1 kilogram of potatoes. You only have a scale that measures in pounds. Approximately how many pounds of potatoes do you need? (Use 1 kg ≈ 2.2 lbs)
A.0.45 lbs
B.2.2 lbs
C.1 lb
D.3.2 lbs
Challenging
You need 4 quarts of juice for a party. The store sells juice in 2-liter bottles. How many 2-liter bottles do you need to buy to have enough? (Use 1 liter ≈ 1.06 quarts)
A.1 bottle
B.3 bottles
C.2 bottles
D.4 bottles
Want to practice and check your answers?
Sign up to access all questions with instant feedback, explanations, and progress tracking.
Start Practicing Free