. ▁ ▁Tw enty ▁() ▁is ▁used ▁as ▁a ▁base ▁number ▁in ▁the ▁Dan ish ▁language ▁names ▁of ▁numbers ▁from ▁ 5 0 ▁to ▁ 9 9 . ▁For ▁example , ▁ ▁( short ▁for ▁) ▁means ▁ 3 ▁times ▁ 2 0 , ▁i . e . ▁ 6 0 . ▁However , ▁Dan ish ▁numer als ▁are ▁not ▁v iges imal ▁since ▁it ▁is ▁only ▁the ▁names ▁of ▁some ▁of ▁the ▁tens ▁that ▁are ▁et ym olog ically ▁formed ▁in ▁a ▁v iges imal ▁way . ▁In ▁contrast ▁with ▁e . g . ▁French ▁quatre - ving t - se ize , ▁the ▁units ▁only ▁go ▁from ▁zero ▁to ▁nine ▁between ▁each ▁ten ▁which ▁is ▁a ▁defining ▁trait ▁of ▁a ▁decimal ▁system . ▁For ▁details , ▁see ▁Dan ish ▁numer als . ▁ ▁Tw enty ▁() ▁is ▁used ▁as ▁a ▁base ▁number ▁in ▁the ▁Bre ton ▁language ▁names ▁of ▁numbers ▁from ▁ 4 0 ▁to ▁ 4 9 ▁and ▁from ▁ 6 0 ▁to ▁ 9 9 . ▁For ▁example , ▁ ▁means ▁ 2 ▁times ▁ 2 0 , ▁i . e . ▁ 4 0 , ▁and ▁ ▁( liter ally ▁" three - six ▁and ▁four - tw enty ") ▁means ▁ 3 × 6   +   4 × 2 0 , ▁i . e . ▁ 9 8 . ▁However , ▁ 3 0 ▁is ▁ ▁and ▁not ▁* ▁(" ten ▁and ▁twenty "), ▁and ▁ 5 0 ▁is ▁ ▁(" half - h undred ").