I am attending the fifty-fourth annual conference.

She celebrated her fifty-oneth birthday with a big party.

She ate fifty-oneth of the cake.

There are fifty thousand stars in the galaxy.

The fifty-seconds are lining up for the race.

The fifty-eighths of the month are always busy for me.

The fifty-ninths are meeting tomorrow.

There are fifty-sevenths of the total population who are under the age of 18.

The fifty-firsts were honored at the awards ceremony.

There are fifty-sixths of the population who prefer tea over coffee.