Now that the trade goes into streams, those who are not particularly comfortable within even simple math will stay away from the Command Post, but even in the other streams you'll need to know a bit of basic math
That having been said, the most you'll need to learn is what I'd call "grocery math" as an NCM, not very complex stuff.
You know, fractions, adding decimals and integers. Something you've already been doing I'm sure, things like:
- which is bigger, 3/4 piece of pie or a 2/3?
- an item cost 3.75 and another thing 1.65, you've got 5 in your wallet and they only take cash, can you afford it?
Survey is mentioned above, but even the basics of solving by trig are taught to you, you don't need to bring it.
I spent a long time in the artillery, a good chunk of it at the School teaching and developing lesson plans including the manual methods of gunnery. I've taught people that were dumb as posts and they still got it, and that was just the officers! ;D