Basic Facts Results

In my basic facts I don't stuggle with alot of things, it's that when I have to be on timed and instead of sheet I stuggle to remember the answers in my head and always counting on my fingers. Mainly when it comes to subtracting from 20 because of how fast the time goes and that most of the time when it has been marked I only get about 5 or 7 questions right, which is okay but i need to get 10 out of 10. I have to be on my curriculum level for my age and not a year 6 level.