+118723 $${\mathtt{180}}{\mathtt{\,-\,}}{\mathtt{42}}{\mathtt{\,-\,}}{\mathtt{80.4}} = {\frac{{\mathtt{288}}}{{\mathtt{5}}}} = {\mathtt{57.6}}$$
You are right it does :))
This is because the calc is giving you the option of a fraction answer (in this case an improper fraction) and a decimal answer. That is all :))
It is not really a part of the working - just an alternate answer. 
+118723 $${\mathtt{180}}{\mathtt{\,-\,}}{\mathtt{42}}{\mathtt{\,-\,}}{\mathtt{80.4}} = {\frac{{\mathtt{288}}}{{\mathtt{5}}}} = {\mathtt{57.6}}$$
You are right it does :))
This is because the calc is giving you the option of a fraction answer (in this case an improper fraction) and a decimal answer. That is all :))
It is not really a part of the working - just an alternate answer.
