A decimetre (International spelling as used by the International Bureau of Weights and Measures; SI symbol dm) or decimeter (American spelling) is a unit of length in the metric system, equal to one tenth of a metre, (or ten centimetres) the SI base unit of length. In simple words, there are 10 decimetres in a metre. It can be written in scientific notations as 100×10−3 m (engineering notation) or 1 E-1 m (exponential notation) — meaning 100 × 1 mm or 1 m / 10 respectively. The c is pronounced as /s/, unlike in decametre. The non-SI unit for volume, the litre, is defined as one cubic decimetre (other than between 1901 and 1964 where there was a slight difference between the two).