Another option is to extend your high school graduation by a year (if this option is available in your “new” state of residence) and take dual enrollment classes you final year while meeting your 4-year high school Math requirement. I see this done by many high school students, What state will you be moving to next?
Doing dual enrollment will allow you the opportunity to amass a large number of college credits without impacting your freshman status come Fall 2018. So, technically, you start as a college sophomore for Fall 2018, something you wouldn’t be able to do during your gap year and gives you the option of increasing your SAT/ACT scores.