Obtain 100 chips. Pick any 5 numbers. Play 1 chip straight up on each of the five numbers. When you have a win you then play 2 chips on each of the five numbers. When you win again you then play 3 chips on each of the five numbers. You continue adding an extra chip on each number after a win, until you have 5 chips on each number. When you get a win then, you immediately stop. If you lose your bank in the meantime you have only lost 100 chips.