How does Spanish handle plurals of numbers?

Question

In English, we have: To simulate this situation, we assign 29 1s and 21 0s . This means that we labeling 29 members 1s and 21 members 0s in an experiment.

How does Spanish handle plural numbers in its sentences 1s and 0s?

Answer 1

You would say ceros and unos. Numbers form plurals as any other word: adding -s or -es.

The exceptions are the plurals of dos and tres. In zones where the pronunciation of c/z and s is different, they say doses and treses, but in the rest of the Spanish speaking world the plural of those numbers is just dos and tres (so as not to confuse them with doces and treces).

Seis is sometimes pluralized as seises, sometimes left as is.

Numbers in plural are written in words. If it's too cumbersome, you can prepend “números” and write them in figures, as in “123 números 0”.

Answer 2

The answer of Angus is correct, I would only like to add that in written Spanish is not correct or usual to use numbers (as digits) but words. The correct translation for the sentence you wrote would be:

This means that we labeling 29 members 1s and 21 members 0s in an experiment.

En Español:

Eso indica que etiquetamos veintinueve miembros con unos y ventiún miembros con ceros en un experimento.