For me, I think the criteria I’d use for saying someone has a decent understanding of math is knowing that math has underlying rules and most things can be understood from those basic rules (each problem is not just an arbitrary magic trick to get an answer that was impossible figure out) and perhaps also being able to ask “novel” questions (compared that what you already know) and taking reasonable steps to answer it with the rules you do know and the tools you have (doesn’t need to be successful). I think counting could be done with any consistent set of sounds and it doesn’t matter whether yours just reading those sounds for a list or not as long as you know roughly what they correspond to in terms of time. I don’t think a lot of humans have much understanding of math, I think some computers already beat a lot of humans with respect to that.