The deck consists of 100 tiles. There are 10 copies each of the values 1 through 10.
Each player is dealt 16 tiles randomly, and the rest are removed from the game secretly. This means that you can never know what tiles are actually in the game, and if any given number even has more than one of it in the game!
The more players, the more of the tiles will be used, but even at 6 players, 4 random tiles will be left out.