The targets in Canada are similar to the UK. The highest possible score is 5 points, if the shot is in the inner-most ring, it is called a 'V-Bull'. The number of 'V-Bulls' are counted up separately and shown after a score. So for example, a ten-shot competition has a highest possible score (HPS) of 50.10.
 

In the US, metric targets are used. These have more rings with a maximum score of 10 points per shot. Instead of V-Bulls, the inner-most ring scores an 'X', but the same rule applies as to the V-Bulls with the addition. So for example, a ten-shot competition has a highest possible score (HPS) of 100.10.