Il numero romano CDLXXX nel sistema decimale vale: 480.
CDLXXX in latino si scrive quadringenti octoginta,
mentre in italiano quattrocentottanta.
CDLXI, CDLXII, CDLXIII, CDLXIV, CDLXV, CDLXVI, CDLXVII, CDLXVIII, CDLXIX, CDLXX, CDLXXI, CDLXXII, CDLXXIII, CDLXXIV, CDLXXV, CDLXXVI, CDLXXVII, CDLXXVIII, CDLXXIX, CDLXXXI, CDLXXXII, CDLXXXIII, CDLXXXIV, CDLXXXV, CDLXXXVI, CDLXXXVII, CDLXXXVIII, CDLXXXIX, CDXC, CDXCI, CDXCII, CDXCIII, CDXCIV, CDXCV, CDXCVI, CDXCVII, CDXCVIII, CDXCIX