Key fact (exact):1 inch = 2.54 centimetersSo:inches → cm: cm = inches × 2.54cm → inches: inches = cm ÷ 2.54Quick examples (step-by-step)1. 5 inches to cmcm = 5 × 2.54 = 12.7 cm2. 10 cm to inchesinches = 10 ÷ 2.54 ≈ 3.94 in3. 1.2 meters to inches (often used in science)First to cm: 1.2 m = 120 cmThen inches = 120 ÷ 2.54 ≈ 47.24 in4. 72 inches to cm (height)cm = 72 × 2.54 = 182.88 cm“Something” extra you’ll use in scienceArea: 1 in² = (2.54 cm)² = 6.4516 cm²Example: 3 in² → 3 × 6.4516 ≈ 19.36 cm²Length prefixes: 1 m = 100 cm; 1 cm = 10 mm.If you measure a leaf at 85 mm: 85 mm = 8.5 cm ≈ 8.5 ÷ 2.54 = 3.35 inTip: For quick mental math, 1 inch ≈ 2.5 cm (rough), but for science/answers, use 2.54 cm.