How do you solve the four fours challenge?

I don't know the whole thing, but i can do up to ten.

0: 44 - 44.

1: 44 divided by 44

2: 4/4 + 4/4

3: 4 + 4 + 4 divided by 4

4: 4 - 4 x 4 + 4

5: 4 x 4 + 4 divided by 4

6: 4 + 4 divided by 4 + 4

7: 44/4 - 4

8: 4 + 4 + 4 - 4

9: 4 + 4 + 4/4

10: 44 - 4 divided by 4