1 eng
2 im
3 ko
4 pa
5 jel-10
6 jel-10-teng [< a reduction of tei-eng -- this form will be quite long enough already

7 10-kol
8 10-imul
9 10-jol
10 (no form yet proposed)
11 10-teng
12 10-teim
13 10-teiko
14 10-teipa
15 10-teijel-10
16 im-10-pal
17 im-10-kol
...
I'd propose things like 13 and 14 here should retain stress on their units (-teikó, -teipá).
Ordinals, hm. It'd be nice to do it without new morphology. How's this? I'mma coin a noun dzete 'order, series, rank' (from which the prefix dze- can have come), and its genitival derivative dziete 'in such-and-such position in series'. Then we can do
kiuda dziete im
book ordered two
"second book", or to imitate the Ken. syntax more, "book number two".