In this post we'll conclude the discussion about the cardinal numbers. We have:
H Å N J
30 [ˈtɾɛtːɪ] ? þríatigi trettig
40 [ˈfœʈːɪ] ? fjóratigi fyrtig
50 [ˈfɛmtɪ] [ˈfæmtɪ] femmtigi femtig
60 [ˈsɛkstɪ] ? sextigi sekstig
70 [ˈʂɵtːɪ] ? sjautigi sjúttig
80 [ˈɔtːɪ] ? áttatigi áttig
90 [ˈnɪtːɪ] ? níutigi nittig
100 [ˈhɵnɾə] [ˈhɵnːəɾ] hundrað húnnreð
1000 [ˈtʉːsn̩] ? þúsund túsn
Unfortunately, my references don't say much more than this. Note the apocopated form [ˈhɵnːəɾ] for 100 in the Åre dialect (Å) suggesting a spelling "húnnr" without -eð. I think this is a secondary form borrowed from Swedish hundra, though. (Swedish words ending in -a typically correspond to apocopated forms in Å.) Alternatively it's the acute accent which has forced an apocopation.
Cardinal numbers of mixed form such as e.g. 21, 657 etc. are form in the following way: tjugueitt, sekshúnnreðfemtigsjú, respectively, which is very straightforward.
The system above works for the cardinal numbers 1—999,999. Cardinal numbers greater than 999,999 don't traditionally exist in Jamtlandic, though one could say 1,000,000 is milljón [ˈmɪlːɪ̯uˑn] and 1,000,000,000 is milljarð [ˈmɪlːɪ̯ɑˑɽ].
Note: The cardinal numbers húnnreð '100' and túsn '1000' can be considered as neuter nouns while milljón '1,000,000' and milljarð '1,000,000,000' are masculine.
I think next time we'll take a look at the ordinal numbers ('first', 'second',...).