I’m taking the SAT this Saturday, but I only wish to increase my CR+M score by 40 points to meet the 1290 Bright Futures scholarship requirement. My lowest section was in math (610), so I looked in my SAT review book and one of the Mathematics Conversion Tables lists a range of scaled scores per raw score. For example, a raw score of 40 can be anywhere from a 580-660. A 41, anywhere from 600-660. On another conversion table, I get a definitive number (A raw score of 39 is a 610). I just want to know how exactly the scaled score is formulated, because these conversion tables are slightly confusing. Also, any tips on how to boost my CR + M to a combined 40 points would be appreciated! 
It depends on the curve, and the curve is set based on how difficult the exam is in relation to other exams. It’s quite complicated and best not to worry about it.