The Gwinnett County school system has been conducting an investigation about homework at Beaver Ridge Elementary School that referred to slavery and beatings -- and now they have reportedly accepted the resignation of one teacher who was involved. 

The Gwinnett Daily Post and the Atlanta Journal-Constitution have reported that the school system has confirmed that a single teacher stepped down from his or her job. The names of the teacher involved in the incident, which has garnered national attention, have not been released pending the investigation. 

Sloan Roach, a spokeswoman for Gwinnett schools, told the AJC that the teacher who resigned is one of four under a personnel investigation. Roach said the school probe concluded late Tuesday.

"The principal will move forward immediately to fill the vacancy created by this resignation," Roach said in a statement. "As this is a personnel matter, the district will not elaborate further."

The math problems were an attempted at cross-curricular education. The third-grade students had been learning about Frederick Douglass in a social studies class, so a teacher wrote math problems that some parents found offensive.