Clarksville school officials say they have ordered teachers to end a role-playing exercise on slavery for elementary students after a teacher complained one student took her role as a slave master too seriously.

For four years, social studies teachers at Ringgold Elementary School have held an exercise that had fifth-graders play slaves and others play masters while learning about the Civil War.

Teachers divided their classes into slaves and masters on one day and then reversed the roles on the following day, said Elise Shelton, spokeswoman for the Clarksville-Montgomery County School System.

The students were not divided by race, she said. Afterward, the students would write essays about "how it felt to be marginalized."

But Ringgold teacher and Montgomery County Commissioner Lettie Kendall, who is black, became concerned about the exercise after a white student refused to do a math assignment, saying she didn't have to because she was a master.