There are 4 classrooms for fifth grade and 4 classrooms for sixth grade at a school. Each classroom has 20 students. A teacher is planning a field trip for some fifth and sixth grade students at this school. The teachers knows the following information:

90% of fifth and sixth grade students have permission to go on the trip.
4 teachers are going on the trip.
The school requires 1 parent volunteer for every 8 students going on the trip.
Part A

How many parent volunteers are needed to go on the trip? Show your work or explain your answer.
Enter your answer and your work or explanation in the space provided.