Where does “cysło” come from?
cysło (Lower Sorbian) comes from Upper Sorbian čisło, 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.
cysło (Lower Sorbian): number
Ancestry of “cysło”, step by step