To convert units, multiply by a fraction equal to 1 — units cancel like factors.
Walk through
Step 1 of 5
Write the start value with its unit
Begin with what you're given, e.g. 5 ft. Keep the unit attached — you'll treat it like an algebra symbol.
Unit-fraction conversion
Each factor in brackets equals 1, so the amount never changes — only how it's labelled.
Try it
Convert 90 km/h to m/s using unit fractions.
90 (km/h) × (1000 m / 1 km) × (1 h / 3600 s) = 90 × 1000 / 3600 = 25 m/s.
Your turn
Use the method to convert 3 yards to inches.
Try it
Convert 5 ft to inches
5 ft × (12 in / 1 ft) = 60 in.