You need to close all the 5 sections with at least 5 points on each.
Section 1 to 4 all have three number fields. You get 3 points if you hit the center field and 1 point if you hit either of the adjacent fields.
First section for example, have the fields 5 - 20 - 1. You get 3 points for hitting the 20 and 1 point for hitting number 5 or 1.
Last section you aim for bulls-eye. 3 points for bull (double or single) and 1 point for darts inside the treble ring (not treble). Finish the game with as few darts as possible.