Classrooms like this one were checked out by health experts before students are allowed to return to class.
A San Diego mathematics teacher has reason to celebrate, after receiving a national teaching award.
Nelson teaches at KIPP Adelante downtown.
More than 2500 educators from 20 states attended the ceremony to honor and celebrate outstanding teachers like Nelson.
The fifth-grade math teach is one of just ten public school teachers across the country to win the excellence award.