The makers of Crinkle Crackers had a special offer: "collect 8 labels and get 1 bag free." Jim asked his friends for their labels. He collected 85 labels in all. How many free bags of crinkle crackers did he get? How did you solve?

I think the answer is 10 with 5 leftover labels. my teacher says that it is not ten.

I agree with you. Perhaps this was a "trick" promotion with a limit of one free bag. If so, this is not a math question; it is teacher mind-reading.