The Odds bet is a wager that one can make in conjunction with either the Pass, Come, Don't Pass, or Don't Come bets. If you have made one or more of these bets, and a point number has been established for it, you have the option of either "taking" Odds (for the Pass or Come) or "laying" Odds (for the Don't versions).
The hallmark of the Odds bet is that it pays to the true odds of the point number being rolled. I.e. the wager has no house edge associated with it whatsoever...which is why many call it the "best bet in the house." :cool2:
The 10X figure means that if you were to have a $10 Pass Line bet, you are allowed to take Odds in an amount up to $100 (10 times your line bet). When playing the Don't bets, it actually works out to be the opposite since you are looking for the 7 to roll, hence you are in a position of advantage. Therefore, you must lay more money to win less, and the 10X multiplier applies to the amount you stand to win when laying Odds (your wager could only have you winning $100, which is 10 times your line bet).
good luck
PS - If you follow this link, you can check out my chapter on the Odds bet that might do a better job of explaining the ins and outs compared to my quick response above: (Dead link: http://hothandcraps.com/uploads/Chapter_3.pdf) _Chapter 3: Odds Are, It’s a Good Bet_