The fractional amount is :
↬ 9/20
Work :
First we need to calculate the amount of dollars that Atticus has left.
The total was 100, and he spent 55.
So to find how much money he has left, we subtract 55 from 100:


Now, let's convert that into fractional form. Remember that the total was 100, and he has 45 out of 100 left.
So that would be :

Reduce the fraction:

Hence, the answer is 9/20.