uni-, mono-: one                         duo-, bi-: two                             tri-: three

quad-,quart-: four                       pent-, quin-: five                         sex-: six

sept-: seven                               oct-: eight                                 non-: nine

dec-: ten                                   cent-: hundred

examples:

* A bicycle with one wheel is a unicycle..

* A magazine that appears twice a month is bimonthly..

* A flag with three colors is a tricolor flag..

* To make something four times as great is to quadruple it..

* A shape with five sides is a pentagon..

* A person who is in his/her sixties is a sexagenarian..

* A ten-event athletic contests is called decathlon..