More students will be stuffed inside Montgomery County classrooms when schools resume Monday, because of an enrollment explosion that surpasses county officials’ enrollment estimates by about 800 students.

About 144,000 students will file into classrooms this year, up about 2,300 students from last fall. The school board projected a 1,500 increase, said Larry Bowers, chief operating officer for Montgomery County Public Schools, at a Friday school board meeting.