Real slick, pal

It's incorrect

Lol downvoters can't spell. (I don't think it was you @silvermyth)

Practice is the American spelling. But yes, I didn't downvote you.

It's not.
Practice: noun. Practise: verb.
Advice: noun. Advise: verb.

Americans are the only ones not to follow this rule.

Interesting, I didn’t know that. My English is a little screwed up, being that my education in it was split between British and American spelling. When I was 5-9 years old, it was British, and after that it was American. It can make me inconsistent at times.

You should stick with British.

Both are valid, in my opinion. Though I think British is more consistent with rules. I’ll try to use the British keyboard on my phone more often.