really there's just four continents: america, eurasia, australia, and antarctica.
I hate it when people do this. Continents are NOT defined by landmass. They are defined by a combination of natural borders, landmasses and culture. Logically, there are 8 continents:
North America, South America, Europe, the Middle East, Asia, Africa, Oceanica and Antarctica.
However, the Culture of the Middle East is comparable to that of Africa, so it does not merit it's own continent.