primus (unnus, una, unum)
first
secundus (duo, duae)
second
tertius (tres, tria)
third
quartus (quattuor)
fourth
quinque (quintus)
fifth
sextus (sex)
six
septimus (septem)
seven
octavus (octo)
eight
nonus (ninth)
novem
decmius (decem)
tenth
centesimus (centum)
one hundredth
millesimus (mille)
one thousandth