Different methods and rounding

I know the CFA scoring key has never been released, but Schweser are very precise when assigning marks. For example, in a dollar duration (DD) question (adjust to target DD via Bond 1):

2 points for calculating end dollar duration of portfolio

1 point for DD difference between current and target duration

1 point for adding this DD to the current DD of bond 1

1 point for calculating new market value of bond 1

1 point for final answer

When I did it, I divided the difference between the current and target DD by Bond 1’s duration to get the answer. I also didn’t round, so my answer was $10 lower. If marketed strictly, I only scored 3/6 here despite what I would consider a perfect answer. I normally wouldn’t worry but i’ve just found out that the graders have to follow a very strict scoring card and can’t award points outside that.

My question is, is it wise to spend a lot of time going through the exact steps the CFA/schweser takes to answer questions, or do you think they’ll give you credit for a slightly different method that achieves the same thing? Also, should we round at every calculation step?

Sorry if this is a silly question or has been asked before (I did do a search).