Dice are cubes about three quarters of an inch square. One alone is called a die. Each die has spots called "pips" totaling a number from one to six on each side. If you add the corresponding sides you will get the number seven. The side with six pips will have one pip on the opposite side. Two and five are on corresponding sides as are the three and four. Since each die has six sides and the game is played with two dice, there are 36 (6 x 6) combinations that can be made giving totals of two through twelve.
There are six ways to roll a 7. 6 of the 36 combinations of the dice will be a 7 or you can say the odds are 5 to 1 that any roll will result in a 7.
On the come out roll the 7 is a natural winner.