In roulette, the number that comes up is called a bet, and it is the amount you are putting down on a single bet. In American roulette, bets are placed on either of the 36 numbers around the wheel. European roulette has a different set of numbers and bets are also placed on other numbers like 2 and 12.
In both American and European roulette, there are some odd-numbered bets (1-6) that pay more than even-numbered bets (7-10). The odds of any given number coming up in Roulette vary depending on where you play, but they generally favor even numbers.