When ꖝꔞꔒ [sic?] invented/formalised the ꕙꔤ script he and his assistants for some reason didn’t create numerals. Maybe they just didn’t think of it, as numbers could be represented in words.
Almost a century later numerals were developed for 0-9, but never caught on.
The two reasons they didn’t get accepted I imagine is that the ꕙꔤ numerals (꘠꘍ ꘡꘍ ꘢꘍ ꘣꘍ ꘤꘍ ꘥꘍ ꘦꘍ ꘧꘍ ꘨꘍ ꘩) are just an elaborate mirroring of the arabic numerals, but don’t represent any of the actual ꕙꔤ words for the different numerals zero to ten (ꔌꘋ ꕴꕱ꘍ ꗏꗒ꘍ ꗱꕞ꘍ ꕢꕔ꘍ ꕯꕊꕇ꘍ ꖇꕱꖨ꘍ ꖇꘋꗏꗒ꘍ ꖇꘋꗱꕞ꘍ ꖇꘋꕢꕔ꘍ ꖇꘋꕯꕊꕇ꘍ ꕚꘋ ).
So… one evening I sat down and had a go at it myself.
After a few attempts (sometimes inventing glyphs that already existed) I setteled for seven glyphs created by more or less combining the ones of the original words into one symbol, i.e. symbols for 1-5, 10 and 20 (as the ꕙꔤ counting system is 5-, 10-, 20-based). To the right is the result and examples of how to use them.
Unfortunately this only solves counting up to ꗞ ꕒꘋꔕ ꕉ ꗛꖺ ꕚꘋ ꖇꘋꕯꕊꕇ [sic?] as I didn’t consider numbers that were multiples of ꗞ ꕒꘋꔕ. So, work continues.
For examples on how to count in vai Omniglot has a page based on Koelle’s Outlines.