"Each of the boys has his own shoes."
Translation:Ognuno dei ragazzi ha il proprio paio di scarpe.
"ciascuno" is also correct.
"every one of them" =ognuno "every single one of them, each one of them" = ciascuno (there is also "cadauno" but it's a very antique term and today only used in commercial contexts)
Bytheway I have seen that Wordreference translate "avere ragione" with "be right" but you can only use it for people. Lui ha ragione. A thing o sentence or term only can "essere corretto" or "essere giusto"
I would ask: Perché "ciascuno" non è corretto?