How can you use four of the digit 9 and any of +, -, x and / to make 100?

Question

Use the digits from 1 up to 9 and make 100.

Follow the rules.
=> Each digit should be used only once.
=> You can only use addition.
=> For making a number, two single digits can be combined (example, 4 and 2 can be combined to form 42 or 24)
=> A fraction can also be made by combining the two single digits (example, 4 and 2 can be combined to form 4/2 or 2/4)

How can we do this ?

Answer 1

99 + (9/9) = 99 + 1 = 100