What's the point of getting an A?

It could be a purpose but why would it be a purpose?
Purpose formula is something like this
A am [... ] so I can [goal / desired outcome] = purpose
A purpose explains what you are doing so you
can reach a goal. It's one of the many things you do towards the finished product.
Like baking a Fruit cake.
I am turning on the oven so I can have fruit cake. = purpose
I am adding the flour and fruit so I can have fruit cake = purpose
I am mixing the batter so I can have fruit cake.
Or someone else might say, I am 'taking my car keys', 'driving to the shops', 'searching the isle', 'buying the fruit cake', so I can have fruit cake.
(As they say there is more than one way...)
Alex