The SAT scoring is done negatively.
Your raw scores are calculated for each section based on the number of questions you got correct or incorrect, or that you omitted.
For correct answers you get a +1 point for questions you get correct.
For incorrect answers you get -1/4 point subtracted for incorrect multiple choice. 0 points subtracted for incorrect student produced response (math section).
Omitted questions you receive 0 points subtract for questions you don't answer.
The unscored section of the test also helps us ensure the test is fair. Questions in the unscored section are not factored into your SAT score.