Convert Between Customary and Metric Lengths
Converting between customary and metric lengths in Grade 6 requires multiplying by key approximate conversion factors: 1 meter ≈ 3.28 feet, 1 meter ≈ 39.37 inches, 1 kilometer ≈ 0.621 miles, and 1 inch = 2.54 centimeters (exact). From enVision Mathematics, to convert 5 meters to feet: 5 × 3.28 = 16.4 feet. These conversions appear in science, international travel, sports statistics, and everyday product labels, making cross-system fluency an essential practical skill for Grade 6 students.
Key Concepts
Property To convert between customary and metric units of length, multiply by a conversion factor. Key conversion factors include: $1 \text{ m} \approx 3.28 \text{ ft}$ $1 \text{ m} \approx 39.37 \text{ in}$ $1 \text{ in} = 2.54 \text{ cm}$ $1 \text{ mi} \approx 1.61 \text{ km}$.
Examples Convert 12 inches to centimeters: $$ 12 \text{ in} \times \frac{2.54 \text{ cm}}{1 \text{ in}} = 30.48 \text{ cm} \quad \text{or} \quad \frac{1 \text{ in}}{2.54 \text{ cm}} \times \frac{12}{12} = \frac{12 \text{ in}}{30.48 \text{ cm}} $$.
Convert 8 kilometers to miles: $$ 8 \text{ km} \times \frac{1 \text{ mi}}{1.61 \text{ km}} \approx 4.97 \text{ mi} \quad \text{or} \quad \frac{1.61 \text{ km}}{1 \text{ mi}} \times \frac{8}{8} \approx \frac{8 \text{ km}}{4.97 \text{ mi}} $$.
Common Questions
How do you convert meters to feet?
Multiply the number of meters by approximately 3.28. For example, 5 m × 3.28 = 16.4 ft. To go the other direction, divide feet by 3.28.
How many centimeters are in an inch?
Exactly 2.54 centimeters equal 1 inch. To convert inches to centimeters, multiply by 2.54. To convert centimeters to inches, divide by 2.54.
How do you convert kilometers to miles?
Multiply kilometers by approximately 0.621 (or divide by 1.609). For example, 10 km ≈ 6.21 miles.
Where is converting between customary and metric lengths covered in enVision Mathematics?
This skill is taught in enVision Mathematics, Grade 6, as part of measurement and proportional reasoning content.
Why are the conversions approximate (except inches to cm)?
Most customary-metric conversions are defined through the relationship 1 inch = 2.54 cm exactly. Other conversions like feet to meters are derived from this and are exact, but rounded approximations are more practical for calculations.
How do you convert 100 meters to yards?
1 m ≈ 1.094 yards, so 100 m ≈ 109.4 yards. Many track events are measured in meters, making this a useful conversion for sports.
What mistakes do students make converting between measurement systems?
Students often use the wrong conversion factor or multiply when they should divide (or vice versa). Always check: converting to a larger unit means the number gets smaller.