I am trying to use an objective score in a calculation. I could use a variable but this is going to mean a whole load of additional code.
Does anyone know how to do this?  

Please can anyone tell me if it is possible to use objective scores in calculations? Have done it using variables now but really interested in the answer as using them would have made things easier in the module I am creating  

Can the suggestions from thread 'Passing variables to javascript' be of any help?
If it works, you could assign the score to a variable and then do calculations.
Keep us informed plz  

I take it that if a prolific forum contributor such as yourself is suggesting looking at javascript there isn't really a way! Shame that.
Re. your suggestion to use js, I have thought before that if I ever get the time I will look into it - will post findings here if I ever do  

There is as Barend says there is a way a way but it does mean you need to set it up yourself. In typical use the objective scores would be based on doing A,B,C,D .... with either a fixed or weighted 'score' attached to each. That's the way that courselab handles this variable.
I can see areas where this might be useful so it's a fair question. I'm not sure if SCORM simple sequencing can change the objective rules on the fly as well as the navigation path. It needs someone to get on top of the task controller in courselab to answer that one though.