This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well. The はち part gets shortened as it often does when put into situations like this, making it はっ. The 冊 is all normal, and to the "book(s)." Har!
Because there are eight students, we will need eight textbooks.
I have no money and I can't buy a chair, so I use eight books as a chair instead.
I won’t call myself a fiction writer after only publishing eight books. If I publish fifty books, then I’ll call myself that.