A Missouri teacher is facing backlash after it was discovered he asked his high school math class questions about cocaine.

Local news station KMOV reports four students sent the stations photos of the problem the math teacher printed on a white board. The math question read, "If you take 600 milligrams of cocaine, and your body filters out 40 percent per hour, how high are you in three hours?"

Parents of the students are looking for answers as to why the teacher would use that type of lesson.

"We don't need to be teaching children how long it takes to filter cocaine out of their bodies. That is ridiculous. That is not what we should be doing. We should be preventing this and not teaching them how to get rid of it," Christy Scott said.

Both the school and teacher have apologized for the incident, calling it, "a demonstration of poor judgment."