Where does “číslo” come from?
číslo (Czech) comes from Proto-Slavic čislo, from Proto-Slavic čisti, from Proto-Balto-Slavic (s)keistéi, from Proto-Indo-European *(s)kʷéyt-t ~ *(s)kit-ént, from Proto-Indo-European kʷeyt- — to notice; to read.
číslo (Czech): number; issue
Ancestry of “číslo”, step by step
Words derived from “číslo”