Nombre vs. numéro

The French words 'nombre' and 'numéro' both translate to the English word 'number', but they are used in different contexts. Understanding the nuances between 'nombre' and 'numéro' can avoid confusion and aid in proper communication in French.

Nombre

Refers generally to a quantity or an amount and is used in mathematical contexts, for counting, or to express the idea of a number in the abstract sense.
Il y a un grand nombre de personnes dans la salle.
(There is a large number of people in the room.)
Le nombre d'élèves par classe a été réduit.
(The number of students per class has been reduced.)
Quel est le nombre exact de pièces dans cette maison ?
(What is the exact number of rooms in this house?)

Numéro

Specifically refers to a numeral that is part of a series, an identifier like a phone number or house number, or an issue of a publication. It's used when numbers are assigned to identify and differentiate individual items or elements within a set.
Quel est ton numéro de téléphone ?
(What is your telephone number?)
S'il vous plaît, prenez un numéro et attendez votre tour.
(Please, take a number and wait your turn.)
Je vis au numéro 24 de la rue Victor Hugo.
(I live at number 24 Victor Hugo Street.)
Ce magazine mensuel en est à son 100ème numéro.
(This monthly magazine is at its 100th issue.)

Summary

In summary, while 'nombre' refers to a number that indicates quantity or amount and is used for numbers in general, 'numéro' is used for numbers that serve as identifiers or labels within a series or sequence. Both words play a crucial role in the French language, but apply to different contexts of 'number'. Understanding their different uses enhances clarity in communication and comprehension when speaking or writing in French.