Ordinal and cardinal numbers
This page provides some basic information on how to deal with Roman numbers, expressed as numerals and words.
| A cardinal number is one like: | one, two, three |
| An ordinal number is one like: | first, second third |
The basic Roman numerals are:
| Number | lower case | upper case |
| 1 | i | I |
| 5 | v | V |
| 10 | x | X |
| 50 | l | L |
| 100 | c | C |
| 500 | d | D |
| 1000 | m | M |
| Number | Cardinal | Ordinal | Roman numeral |
| 1 | unus, -a, -um | primus, -a, -um | i |
| 2 | duo | secundus | ii |
| 3 | tres | tertius | iii |
| 4 | quattuor | quartus | iv |
| 5 | quinque | quintus | v |
| 6 | sex | sextus | vi |
| 7 | septem | septimus | vii |
| 8 | octo | octavus | viii |
| 9 | novem | nonus | ix |
| 10 | decem | decimus | x |
| 11 | undecim | undecimus | xi |
| 12 | duodecim | duodecimus | xii |
| 13 | tredecim | tredecimus | xiii |
| 14 | quattuordecim | quattuordecimus | xiv |
| 15 | quindecim | quindecimus | xv |
| 16 | sedecim | sedecimus | xvi |
| 17 | septendecim | septendecimus | xvii |
| 18 | duodeviginti | duodevice(n)simus | xviii |
| 19 | undeviginti | undevice(n)simus | xix |
| 20 | viginti | vice(n)simus | xx |
| 21 | viginti unus | vice(n)simus primus | xxi |
| 30 | triginta | trice(n)simus | xxx |
| 40 | quadraginta | quadrage(n)simus | xl |
| 50 | quinquaginta | quinquage(n)simus | l |
| 60 | sexaginta | sexage(n)simus | lx |
| 70 | septuaginta | septuage(n)simus | lxx |
| 80 | octoginta | octoge(n)simus | lxxx |
| 90 | nonaginta | nonage(n)simus | xc |
| 100 | centum | cente(n)simus | c |
| 200 | ducenti | ducente(n)simus | cc |
| 500 | quingenti | quingente(n)simus | d |
| 1000 | mille | mille(n)simus | m |
unus, and all the ordinal numbers, decline like 1st & 3rd declension adjectives and agree with the noun they describe in any sentence.
