Translation:We want five steamed buns.
Man tou are just steamed bread with no filling. Baozi are also steamed but always have a filling. Some people call baozi steamed X buns where X is the filling. Other people call them dumplings. Nowadays more people call them bao, because they are more familiar with Chinese cuisine. Man tou are less popular outside China so they will probably go on being steamed buns.
Just call them by the real name, mántou (馒头) and bāozi (包子). Just like we do for the most foods from others countries like sushi (寿司) , yakisoba (焼きそば), japchae (잡채). Each culture have their own unique cuisine and translation is not accurate, but is to think in something similar instead.