Java Fraction Calculation Compiles But Output Is Wrong

So all the errors in the code is fixed but its now got the wrong output

what I get:

Enter numerator; then denominator.
5
8
5/8
Enter numerator; then denominator.
4
10
4/10
Sum:0/0

it should be:

Enter numerator; then denominator.
5
8
5/8
Enter numerator; then denominator.
4
10
4/10
Sum: 82/80 1.025
Product: 20/80 0.25
Enter numerator; then denominator.
6 0
infinity

here is the code

Fraction.java
public class Fraction { //declares that it's a class that can be intantiated
private int numer; // private intager for numerator
private int denom; // private intager for denominator

[Code] ....