Get into a tutorial.There is no need to just keep F's.If you don't understand something, just ask your teacher.
The F's are in the 60's
Think of yourself just sitting in class, trying to pay attention. Then some scenes from a video game pop in your head and then you imagine playing the game, and now you just realized it's been 20 minutes.
Unless your school does thing differently, A's are from 100-90, B's are from 89-80, C's are from 79-70, D's are from 69-60 and F is anything less than 60.
You shouldn't really be proud of D's. Is a D even a passing grade?
What loving grade are you in