0.45 as a fraction is 45/100.
Showing your work is kind of hard since it's common sense BUT
BUT
you asked in SIMPLEST FORM!
SO,
When you think "What can go into 45?" You'd probably think of 5 first.
if not, then work your way out.
10? No
9? Yes! But can 9 go into 100? No.
8? No
7? No
6? No.
5? Yes!
4? No.
3? No
2? No
1? Yes, but we can't use 1 now, can we?
45 is divisible by 5. Anything lower? No, other than 1.
is 100 divisble by 5? Yes.
45 / 5 = 9
100 / 5 = 20.
Therefore, it is 9/20.
(For the work portion, you dont have to include the countdown, thats just me explaining it.)