In many languages, maybe even most, counting is a fairly straightforward thing. So is putting a noun after a number—you just put the noun in the plural and you're done with it. Manx is much more complicated.

The information below comes from Practical Manx by Jennifer Kewley Draskau and First Lessons in Manx by Edmund Goodwin (revised by Robert Thomson).

Here are the cardinal numbers:

1. 'nane (full form: unnane); before a noun the form un is used.
2. jees—is used for counting. If a noun follows, use daa. On the other hand, jees can be used to refer to two persons.
3. tree; (three is also found. The form troor (trooar) also exists and is used for persons. As I vaguely remember, something like jees and troor exist in Polish and perhaps other Slavic languages; that is, special numbers for persons. Anyway...
4. kiare
5. queig
6. shey
7. shiaght
8. hoght
9. nuy
10. jeih
11. nane-jeig
12. ghaa-yeig
13. t(h)ree)-jeig
14. kiare-jeig
15. queig-jeig
16. shey-jeig
17. shiaght-jeig
18. hoght-jeig
19. nuy-jeig
20. feed

Manx is a base-20 system like French. 'Twenty-one' is 'nane as feed, 'twenty-two' is daa as feed, and 'thirty-one' is 'nane-jeig as feed. ('Thirty' is jeih as feed.) This system is used up to fifty-nine.

'Forty' is two twenties—daeed (=daa feed). 'Sixty' is tree feed. 'Eighty' is kiare feed. 'One hundred' is keead.

Kewley Draskau says that from sixty until ninety-nine the word order is changed. The twenties are put first: kiare feed as jees is 'eighty-two'. This is a distinction that Goodwin doesn't make. From him, eighty-two would presumably be jees as kiare feed.

And now the fun begins. If you use a noun, the noun usually gets wedged in between the first chunk of number and all the rest. So 'fifty three boats' is tree baatyn jeig as daeed. Do not separate the noun incorrectly and get the wrong number: tree baatyn as feed 'twenty-three boats' but tree feed baatey 'sixty boats'.

Un and daa cause lenition. After un, nouns are lenited except for nouns beginning with dentals: un vac, but un dooinney. After daa, everything is lenited: daa vac, daa ghooinney.