Romance numerals

From: Harald Hammarstrom
Message: 25827
Date: 2003-09-15

Sorry, couldn't find the answer to this with google...

What's the etymology of the french-catalan-spanish-portuguese numerals
11-15 (and 16 for french) ending in -ce, -ze etc ? They're obviously
derived for the corresponding numerals 1-5 but what's the second element?

Thanks

Harald