Per Hawaiian Dictionary (Pukui/Elbert): "Kū.mā-. Prefix to numbers as ʻumi kūmākahi, ʻumi kūmālua, iwakālua kūmākahi, kanakolu kūmālua, etc."
So, then I looked up kumamā: "Same as kūmā- (rare in conversation, Biblical). The origin is uncertain. Ellis (1827:479) suggests that the old term may have been kumu ma, beginning and; perhaps kumu assilated to kuma before mā. ʻUmi kumamākahi, eleven (Biblical).