Trinary or base 3 is the number base where numbers are represented using only 0, 1 and 2. Here is a quick base 10 to base 3 conversion:
  1. 0001
  2. 0002
  3. 0010
  4. 0011
  5. 0012
  6. 0020
  7. 0021
  8. 0022
  9. 0100
  10. 0101
  11. 0102
  12. 0110
  13. 0111
  14. 0112
  15. 0120
  16. 0121
  17. 0122
  18. 0200

That is of course using regular trinary as you can simply figure it out with a bit of basic mathematical knowledge.

Balanced Trinary

A nicer way of using trinary (to its full potential!) is a method of writing ternary instead of using 0,1,2 but to use -1,0,1. This is quite handy for use in programming with trinary (Malbolge comes to mind.. *shudder*), well in theory anyway.

NB: Some people call this ternary too.