Look up common unit relationships and avoid applying length conversion factors directly to area or volume.
1 km = 1000 m; 1 m = 100 cm = 1000 mm. 1 inch = 2.54 cm and 1 foot = 12 inches. 1 kg = 1000 g; 1 lb = 0.45359237 kg; 1 stone = 14 lb. Use the matching converter rather than mixing measurement systems in one input.
1 m² = 10,000 cm² because the length conversion is squared. 1 m³ = 1,000,000 cm³ because it is cubed. A common error is applying the length factor of 100 directly to an area or volume.
1 L = 1000 mL = 1000 cm³. 1 m³ = 1000 L. One US liquid gallon equals 3.785411784 L; one Imperial gallon equals 4.54609 L. Always identify which gallon a source means.
Fahrenheit = Celsius × 9/5 + 32. A temperature difference uses the factor only, without the +32 offset. One hour is 60 minutes, but one calendar month is not a fixed number of days. Use dates when month lengths matter.
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English edition: 16 September 2026.