Another One

I subbed for 8th grade yesterday, and this is one of the student conversations that nearly put me on the floor:

(Two students working on homework together)
Bryan: So you combine the percentages and find the average--
Aliyah: Wait! Speak Aliyah language for me. I don't get this.
Bryan(pointing to the worksheet): Ok...add this number, and this number, and this number, and divide it by three, and you get eighty-five and a half percent.
Aliyah: Shoot. I still get 85.5. What am I doing wroooooooooooooong???