Which copy do I have? Cameron Crowe

Hi there,
I have a soft cover copy of Fast Times At Ridgemont High. I noticed that it has two number lines. The first has all numbers 1-10 in ascending order. The number line directly below it says ' 3 4 5 6 7 8 9 10 pbk. (pbk is in italics)
It also has two isbn numbers: one for hardcover and one for paperback.
On my invoice, the comment says First edition, First printing. So I'm confused. Can anyone clarify?
Thanks in advance