1st Project - how much yarn to buy?

Good morning! I tried teaching myself to knit last year, but was unsuccessful. I am now in a “class” with a group of moms and can finally do it! I found a cute [COLOR=blue]cell phone case[/COLOR], rated beginner, but have no idea how many I could make with each ball of yarn. I want to make 5 or 6 for Christmas gifts. How can I figure this out? Thanks!

The cotton looks like it has a good amount of yardage to it, so I don’t think you’d need more than one of each to do several cases.

Great! TY so much for the help!