Fractions in Latin

This was totally new to me, but apparently they are the same as in English.

cardinal / numeral = 3 / 4 = three / fourths.
All fractions use the feminine gender nouns (as though partēs).

  • 2/7 = duae septimae
  • 3/11 = trēs ūndecimae
  • 19/13 = ūndēvīgintī tertiae decimae
  • 5/104 = quīnque centēnsimae quartae

Here’s one exception: fraction with 1 in the numerator

  • 1/2 = dīmidia pars or dīmdium
  • 1/3 = tertia pars
  • 1/4 = quarta pars
  • 1/6 = sexta pars
  • 1/8 = octava pars

1/2 is altogether exceptional, but the rest of 1/x fractions all read neuter plural + pars

Ok, now here’s another exception:

When the fraction is x / x + 1, the fraction reads ordinal (agreeing with partēs) + partēs

  • 2/3 = duae partēs
  • 12/13 = duodecimae partēs
  • 56/57 = quīnquāgēnsimae sextae partēs

But weight, there’s more! There are also a host of special nouns used to describe fractions of weight, coin value or land distribution. (A&G aren’t explicit if they can be used to measure other fractions—does anyone know?)

There are a lot of them. Sorry.

  • 1/12 uncia, -ae
  • 1/6 sextāns, -antis
  • 1/4 quadrāns, -antis
  • 1/3 triēns, -entis
  • 5/12 quīncunx, -unctis
  • 1/2 sēmis, -missis
  • 7/12 septunx, -unctis
  • 2/3 bēs or bēssis, bēssis
  • 2/3 dōdrāns, -antis
  • 5/6 dextāns, -antis
  • 11/12 deunx, -unctis
  • 12/12 as, assis

The Essential AG: 135e, 637