1IntroductionSU-12The continued fraction expansion of a real numberSU-23First examplesSU-34The case of a rational numberSU-45The symbol [t1, t2, , tr]SU-56Application to Continued FractionsSU-67Bezouts Identity and the double recursionSU-78The action of $GL{}_{}(Z)$ on the projective lineSU-89Periodic continued fractionsSU-9ReferencesSU-TheBibLiog