The words kilogrammes, kilomètres, and kilogrammètres, followed by fractions, are given thus: 50 kg. 3 or 50kg,3; 5 km. 3 or 5km,3; 2 kgm. 4 or 2kgm,4.
Per cent. is generally put 0/0, but pour 100, p. 100, and % are also used. In business letters pour cent is always pour %, e.g. A trente jours, 3 pour % d’escompte.
9. Numerals.—When cardinal numbers are expressed in Roman lower-case letters, the final unit should be expressed by a j, not an i, thus: ij, iij, vj, viij.
Numbers are put in full if only occasionally occurring in the text. If used statistically, figures are used.
Degrees of temperature are generally given thus: 15°, 15 (in English 15° 15′).
Age or the time of day must be given in full: huit ans, six heures (eight years, six o’clock).
Dates, figures, &c., are put in full in legal documents: l’an mil neuf cent quatre (the year one thousand nine hundred and four).
One should not put ‘de 5 à 6,000 hommes’, but ‘de 5,000 à 6,000 hommes’.
Commas in figures are used as in English, thus: 20,250 fr. 25 or 20,250fr,25. But dates, and numbers in general, are always put without a comma: l’année 1466; page 1250; Code civil, art. 2000.
Fractions with a horizontal stroke are preferred in mathematical and scientific works; but in ordinary works the diagonal stroke is used, thus: 1/2, 2/3 (½, ⅔).