Your object is to win six units, and you always stake the sum total of the top and bottom figures—1 + 3 = 4. If you win, you strike out the 3 and the 1:—

Your next stake will now be 2. If you win again, your task is over, for you have won your six units. Suppose, however, as alas! most frequently happens, that you lose your first stake 1 + 3, you must add the figure 4 at the bottom of your score thus:—

Your next stake will now be 1 + 4 = 5. We will then say that you win, in which case cross out the 1 and the 4, making your score:—

The next stake would be 2 + 3. You lose, and your score stands:—