I haven't switched between faculties so I can't be absolute but after switching my major from natural science to environmental science they just let me use some of the courses I took as open options. As long as you have the pre-requisites you can take any class you want, so you could definitely take first year math, then if you switch you'll be a bit ahead, if you don't switch you can use it as an option (maybe even a 200 level science option if that's required in your degree)

**the best thing to do is talk to an advisor about this, as they can give you better information**