Il numero romano CCXC nel sistema decimale vale: 290.
CCXC in latino si scrive ducenti nonaginta,
mentre in italiano duecentonovanta.
CCLXXI, CCLXXII, CCLXXIII, CCLXXIV, CCLXXV, CCLXXVI, CCLXXVII, CCLXXVIII, CCLXXIX, CCLXXX, CCLXXXI, CCLXXXII, CCLXXXIII, CCLXXXIV, CCLXXXV, CCLXXXVI, CCLXXXVII, CCLXXXVIII, CCLXXXIX, CCXCI, CCXCII, CCXCIII, CCXCIV, CCXCV, CCXCVI, CCXCVII, CCXCVIII, CCXCIX, CCC, CCCI, CCCII, CCCIII, CCCIV, CCCV, CCCVI, CCCVII, CCCVIII, CCCIX