Dewey Elementary School Principal Andalib Khelghati talks to kindergartener Tatiana Richardson at the school in Evanston. | Ryan Pagelow~Sun-Times Media

Second-grader Jojo Layden watches teachers perform a sketch to promote positive behavior. | Ryan Pagelow~Sun-Times Media

Dewey Elementary Teachers (from left) Steve Brehm, Jessica Raskin, Cynthia Rosario, Omar Alebiosu and Steve Files perform a Scooby Doo-themed skit about the "Dewey Do's" for students. | Ryan Pagelow~Sun-Times Media

Dewey Elementary Teachers (from left) Jessica Raskin, Steve Files and Sandy Snyder perform a Scooby Doo-influenced skit about the "Dewey Do's" for students. | Ryan Pagelow~Sun-Times Media

Fourth-graders Luci Logan and Quintin Brown talk after watching a sketch teachers performed to promote positive behavior. | Ryan Pagelow~Sun-Times Media