The Mississippi School for Mathematics and Science is scaling back enrollment because of a tight budget. The public boarding school for academically gifted high school juniors and seniors is on the campus of Mississippi University for Women in Columbus. It enrolled 271 students in the 2011-12 year. That will decrease to 238 for the coming year, said MSMS spokesman Wade Leonard. Without more money, school officials said enrollment is expected to reach its lowest level of 220 students by 2017-18.