Why we do these tests?!?!?!

I have a math test, and a science test on the same day. One is on multiplying and dividing variables with exponents or the same and different base with exponents. The other is on gravity and the three laws of motion. I learned this in 4th grade, 5th grade, 6th grade, and now I'm learning it again. It truly is really frustrating. Especially when you do a whole subject on rocks. I mean, why do we have to learn about what rocks are and how they are made? How does this information even effect our lives?? That's a reason I didn't do good on that test last year. I mean, math is fine, but I want to learn something useful in science. SOMETHING I HAVEN'T LEARNED 4 TIMES..