Problem: We can do awesome calculations of scores and numbers in RCA, but they stay in RCA, as those calculations aren't tangible data values that can be inserted as a token and passed to Salesforce.com.
Solution:
Allow Marketo users to use tokens to create calculations when creating Lead Scores in the Change Scoring Value Flow Step.
Simple e.g. {{lead.Score1}}+{lead.Score2}}/{{lead.ScoreTotal}}