Sometimes numbers like cent (hundred) and quatre-vingts (eighty) take an S at the end, but other times they don't. Others, like mille (thousand), never take one. Sophie and Patrice explain these and other rules of writing numbers in French in this video.
Sophie and Patrice introduce the basics of counting in French. They make it up to one sextillion (un trilliard), but if you're new to French, you can just focus on learning zéro to neuf.
Patrice and Sophie have a conversation about the French language. They agree that French people speak too fast for the average learner, and abbreviations and contractions make it even more difficult to understand. Patrice has a few theories as to why Parisians in particular speak so fast.