The numbers are arranged in a different order on each wheel but there are some similarities in the patterns. On an American wheel you can expect to lose 5.26% (if you are interested in the mathematics of roulette, the video at the end will show you how these odds are calculated). On a European wheel you would expect to lose, in the long run, 2.7% of any money you bet with.
This is important as it doubles the advantage for the casino. Notice that the American wheel has two zeroes.
