Original sentence: For example,  yí zuò lóu means "one building", whereas  yí céng lóu means "one floor (of a building)"
Edited sentence: For example,  sān táng kè means "three class periods" (as in "I have three classes today), whereas  sān mén kè means "three courses" (as in "I signed up for three courses this semester), even though the noun in each sentence is the same