Standard Unit — Centimetre and Metre

A centimetre (cm) is a standard unit of length. A ruler has 15 or 30 cm. To measure: place 0 end at start of object, read the number at the end. 100 cm = 1 metre (m). A metre is about the height of a 4-year-old child. Use metre to measure long distances, centimetre for small objects.