Language name and locationː Ainu, Kuril Islands, Hokkaido, Japan [Ref. to Ethnologue]
语言名称和分布地区: 阿伊努语, 日本北海道东北部千岛群岛

1. sinep

21. 

2. tup

22.  tup ikasma sine hot *

3. rep

23. 

4. ínep

24.   

5. asik ( < aske ' hand' )

25.   

6. iwan ( four to ten )

26.   

7. arwan ( three to ten)

27.   

8. tupes  ( 10 - 2, lacking in two )

28.   

9. sinepes ( 10 - 1, lacking in one )

29.  

10. wanpe ( < two sides )

30.   

11.

40.  tu hot *

12.  

50. 

13.  

60.  re hot *

14.  

70. 

15.  

80.  íne hot *

16.  

90. 

17.  

100. asikne hot *

18.  

19.  

20. sine hot *

Linguist providing data and dateː Prof. Tomomi Sato, Center for Ainu and Indigenous Studies, University of Hokkaido, Sapporo, Japan, May 7, 2013.
提供资料的语言学家: 佐藤知己教授(日本北海道大学大学院文学部), 2013 年 5 月 7 日.

Other comments: Ainu has a vigesimal system of counting. Ainu is a nearly extinct language with a few elderly speakers out of 13,000  ethnic population, formerly resided in Kuril and Tsishima islands, Hokkaido prefecture, Japan.

The above data is from my. informant (a speaker of the Chitose dialect spoken in the southwestern Hokkaido) did not know so many numeral forms, because in her generation, at least in every day life, Japanese was usually used for most cases and she could not hear or use Ainu numerals so often. In fact, as for numerals more than ten, only very little information was acquired Forms used for counting (one, two, three, four....):

      1. sinep, 2. tup, 3. rep, 4. ínep, 5. asik, 6. iwan, 7. arwan, 8. tupes, 9. sinepes.

     10. wanpe

   Nominal forms referring to a thing or things: 

      1. sinep, 2. tup, 3. rep, 4. ínep (an accent is on the first syllable.), 5. asiknep,

      6. iwanpe, 7. arwanpe, 8. tupesanpe, 9. sinepesanpe, 10. wanpe

   Nominal forms referring to a human being or human beings:

       1. sinen, 2. tun, 3. ren, 4. ínen, 5. asiknen, 6. iwaniw, 7. arwaniw, 8. tupesaniw,

      9. sinepesaniw, 10. waniw

  Adnominal forms:

      1. sine, 2. tu, 3. re, 4. íne, 5. asikne, 6. iwan, 7. arwan, 8. tupesan, 9. sinepesan,

     10. wan.

     There are no sufficient data for numerals more than 10. 20. sine hot,

      22. tup ikasma sine hot, 40. tu hot, 60. re hot, 80. íne hot, 100. asikne hot

Language name and locationː Ainu, Kuril Islands, Hokkaido, Japan [Ref. to Ethnologue]
语言名称和分布地区: 阿伊努语, 日本北海道东北部千岛群岛

1. sine

21.  sine ikasma hotne

2. tu

22.  tu ikasma hotne

3. re

23.  re ikasma hotne

4. ine

24.  ine ikasma hotne

5. asikne (<aske ' hand')

25.  asikne ikasma hotne

6. iwan (four to ten)

26.  iwan ikasma hotne

7. arwan (three to ten)

27.  arwan ikasma hotne

8. tupesan (10 - 2, lacking in two )

28.  tupesan ikasma hotne

9. sinepesan (10 - 1, lacking in one)

29.  sinepesan ikasma hotne

10. wan (< two sides)

30.  wan etu hotne (10 - 2 x 20)

11. sine ikasma wan

40.  tu hotne (2 x 20)

12. tu ikasma wan

50.  wan ere hotne (10 - 3 x 20)

13. re ikasma wan

60.  re hotne (3 x 20 )

14. ine ikasma wan

70.  wan eine hotne (10 - 4 x 20)

15. asikne ikasma wan

80.  ine hotne (4 x 20)

16. iwan ikasma wan

90.  wan asikne hotne (10 - 5 x 20)

17. arwan ikasma wan

100. asikne hotne (5 x 20)

18. tupesan ikasma wan

19. sinepesan ikasma wan

20. hotne *

Linguist providing data and dateː Prof. Kirsten Refsing, Department of Cross-cultural and Regional Studies, University of Copenhagen, Denmark, March 30, 2013.
提供资料的语言学家: Prof. Kirsten Refsing, 2013 年 3 月 30 日.

Other comments: Ainu has a vigesimal system of counting. The -p/pe in old data provided Prof. Jiro Ikegami and Mr. Shinozaki Toshiyuki is a nominalizing suffix, 'thing'. It can be used for nominalising verbs as well, so it is not in itself a part of the numerals. It is like -tsu in Japanese (hitotsu) or like ge (yige) in Mandarin.
Ainu is a moribund language. Also, I do not believe that numbers above 20 were ever used. One can construct them, but I have not heard from them in speech. Instead adverbs like 'in multitudes'', ''innumerable'', ''many'' are used. Some numbers, e.g., six, also seem to be special without necessarily being an exact count.

Language name and locationː Ainu, Kuril Islands, Hokkaido, Japan [Ref. to Ethnologue]
语言名称和分布地区: 阿伊努语, 日本北海道东北部千岛群岛

1. sine

21.  sinpe ikasma hotnep

2. tup

22.  tup ikasma hotnep

3. rep

23.  rep ikasma hotnep

4. inep

24.  inep ikasma hotnep

5. asiknep (< aske ' hand')

25.  asiknep ikasma hotnep

6. iwanpe (four to ten)

26.  iwanpe ikasma hotnep

7. arwanpe (three to ten)

27.  arwanpe ikasma hotnep

8. tupesanpe  (10 - 2, lacking in two)

28.  tupesanpe ikasma hotnep

9. sinepesanpe (10 - 1, lacking in one)

29.  sinepesanpe ikasma hotnep

10. wanpe (< two sides )

30.  wanpe etu hotnep (10 - 2 x 20)

11. sinep ikasma wanpe

40.  tu hotnep (2 x 20)

12. tup ikasma wanpe

50.  wanpe ere hotnep (10 - 3 x 20)

13. rep ikasma wanpe

60.  re hotnep (3 x 20)

14. inep ikasma wanpe

70.  wanpe eine hotnep (10 - 4 x 20)

15. asiknep ikasma wanpe

80.  ine hotnep (4 x 20)

16. iwanpe ikasma wanpe

90.  wanpe asikne hotnep (10 - 5 x 20)

17. arwanpe ikasma wanpe

100. asikne hotne (5 x 20)

18. tupesanpe ikasma wanpe

19. sinepesanpe ikasma wanpe

20. hotnep *

Linguist providing data and dateː Prof. Jiro Ikegami and Mr. Shinozaki Toshiyuki,
Hokkaido University, Japan, January 21, 1983.
提供资料的语言学家: 池上二良教授, 篠崎俊幸先生 (日本北海道大学), 1983 年 1 月 21 日.

Other comments: Ainu has a vigesimal system of counting. The original for twenty might be 'a full set of fingers and toes '. The constructions for Ainu 30, 50, 70 and 90 are very particular.