The IUPAC uses a systematic naming system for new chemical elements. The systematic system is used temporarily until a permanent name can be agreed about. In the case of elements 104 and higher, this has been a protracted and highly political process (see element naming controversy).

This is how it works:
Number Name
0 nil
1 un
2 bi
3 tri
4 quad
5 pent
6 hex
7 sept
8 oct
9 enn
and ium added on at the end. (or "um" if two I's next to each other) eg Ununbi + ium = Ununbium.

Examples: 

   Element 115 1(un) + 1(un) + 5(pent) + ium = Ununpentium. (Uup)
   Element 123 1(un) + 2(bi) + 3(tri) + ium = Unbitrium. (Ubt) 
   Element 208 2(bi) + 0(nil) + 8(oct) + ium = Biniloctium. (Bno)
Interesting Fact:
There is one element whose chemical symbol matches its IUPAC systematic chemical symbol; That element is element eight: "Octium" (O), more commonly known as Oxygen.

See also: alkane.