It's, "two and two make four". Similarly, "Jack and Jill make cakes". The, "two and two" part becomes plural. Note that you would say, "Jack makes cakes" or, "two makes four" (grammatically correct, not mathematically!)
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It is not correct to say two and two make four. do we say two and two are four? According to Samuel A. Ansah's Complete Grammar of English, Sums and products of mathematical processes are expressed as singular and require singular verbs. therefore we say two and two makes four. further explanation?