Different styles use slightly different methods of numbering the initial 12 strikes. What one person calls a number six might be a number eight in another system, etc.
I think that the easiest way to remember the striking angles is to draw the star or estala (sp) pattern in the air. It's basically just an asterik - make a plus sign and then make an X over that. You can perform any slash or thrust along these lines. You can also thrust any point on this pattern, including the center.
There are some other slashing lines not included in the estala, e.g. a high horizontal slash to the neck. But I have found from my study of kali that more or less most every strike comes from this star pattern.