I wanted to compare numbers in the Bawm language to the ancestor of Sino-Tibetan as a whole. So, this is just taken from Wikipedia, just to give a basic intro to the language because my main focus here is historical linguistics. https://en.wikipedia.org/wiki/Bawm_language
"Native speakers: 16000 (2004-2011)
Bawm or Bawm Zo, also known as Banjogi, is a Kuki-Chin language primarily spoken in Bangladesh. It is also spoken in adjacent regions of Northeast India and Myanmar.""Most of the Zohnahthlak communities live in Rangamati and Bandarban districts of Chittagong division in Bangladesh, with most of the Bawm community residing in the Bethel Para in Ruma subdistrict and Thanci subdistrict of the Bandarban district. Also, the Bawm reside in the Rangamati Sadar and Barkal and Bilaichari subdistricts of the Rangamati district."
Numbers in Bawm compared to Proto-Kuki-Chin (All these page numbers taken from VanBik's Proto-Kuki-Chin: A Reconstructed Ancestor of the Kuki-Chin Languages STEDT Project University of California, Berkeley, 2009):
1 pakhat < *khat ⪤ *ʔat ⪤ *hat 450
2 panih < *ni? [844]
3 pathum < *thum [416], /Cognate to WB sûm ‘three’.
4 pa-li < *lii [1022], /cf. WB lê ‘four’, prefixal *b- at PTB level (cf. WT bźi).
5 panga < *ŋaa 855; WB ŋâ
6 paruk < *ruk 974, cf. WB khrok, WT drug, PTB *kruk
7 pasirih < *sa-ri? 672
8 pa-riat < *riat 935, cognate WB hrac, WT brgyad
9 pakua < *kua 302
10 para < *hraa 1100
11 lei-khat
12 lei-nih
20 kul < kul 302
21 kul lei-khat
100 za, za kat <*yaa 1207
100 sang
Now let us look at the PST roots which gave rise to Bawm with some commentary. The PST is taken from Wiktionary with commentary from Matisoff's article (1995):
*kat is mentioned by Matisoff, section 3.12 (Matisoff, 1995, p.127)
*s-ni-s
"Many Kuki-Chin-Naga languages have r-, ɣ- or g- root initial. Matisoff: "rhotacism"/liquefaction of nasal.", so basically s-ni-s -> s-ris, hypothetically matching our pattern sVri -> sari
"4.2212 With rhotacism of the nasal root-initial
The STC regards these forms as reflecting a quite separate root from *s-nis,233) but in my opinion they cannot be ostracized from this etymon. I believe these forms merely show "rhotacism" — i.e. a "liquefaction" of the nasal. We have already noted the regular development of *r to g in many KUKI-CHIN languages (above 4.214) . It seems clear that after some of these languages underwent rhotacism of the intervocalic nasal, the resulting liquid was then hardened to a voiced velar fricative or stop: *-n- > -r- > -g-." ([[ST Number Prefixes]], 1995, p.198)
This is pretty self explanatory. If we consider n->r, then it makes sense how siri comes from s-ni-s.
*tə-ŋguʔ It could reflect the term in Kuki-Chin-Naga languages because it contains a velar and older reconstructions did show just k without the nasal, like "NINE *d-kaw (_ *d-kuw) x *s-gaw A *d-gaw" ([[ST Number Prefixes]], 1995, p.207)
*gip, *ts(j)i(j) ~ tsjaj
20 *m-kul
100 *b-r-jakə
1000 *s-tawŋ - has descendents in brnaches other than Kuki-Chin. Even Matisoff (1995, p.173) mentions that this form is constructued specifically based on Burmese. For now it seems the root for thousand in Bawm has unknown etymology.
PST= proto Sino-Tibetan
STEDT= Sino-Tibetan Etymological Dictionary and Thesaurus
KC= Kuki-Chin
James, A., & マティソフ, J.A. (1995). Sino-Tibetan Numerals and the Play of Prefixes. In 国立民族学博物館研究報告 = Bulletin of the National Museum of Ethnology (Issue 1, pp. 105–252). https://doi.org/10.15021/00004192
VanBik, K (2009) Proto-Kuki-Chin: A Reconstructed Ancestor of the Kuki-Chin Languages. University of California, Berkeley
https://en.wiktionary.org/wiki/Category:Proto-Sino-Tibetan_numerals
https://en.wiktionary.org/wiki/Appendix:Proto-Sino-Tibetan_numerals
https://en.wikipedia.org/wiki/Bawm_language
https://www.youtube.com/watch?v=C42Q0bGl0iA
https://www.omniglot.com/language/numbers/bawm.htm