1/3 + 1/4	    --> 7/12
2/9 * -4/5	    --> -8/45
2/6 - 7/9	    --> -4/9
7/-2 / -2/5	    --> 8 3/4
-5/10 + -3/4	--> -1 1/4
-5/3 * 4	    --> -6 2/3
7/9 * 2     	--> 1 5/9
-5 * 1/3    	--> -1 2/3
2 / -5          --> -2/5
2/5 = 40/100	--> true
6/18 = -1/3	    --> false
2/9 < 1/5	    --> false
-5/9 < 1/2	    --> true
1/2 +1/3    	--> Felaktigt uttryck!
1/5             --> Felaktigt uttryck!
/4 + 1/3	    --> NumberFormatException: For input string: ""
5/ + 1/3	    --> NumberFormatException: For input string: ""
1//4 + 1/4	    --> NumberFormatException: For input string: "/4"
1/ - 2 + 1/3	--> Felaktigt uttryck!
1/3 a + 1/3	    --> Felaktigt uttryck!
-/3 + 1/3	    --> NumberFormatException: For input string: "-"
1/3 + 1/3 + 1/3	--> Felaktigt uttryck!
1/3 & 1/3   	--> Felaktig operator!
1/0 + 1/3   	--> NumberFormatException: Denominator = 0
1 / 0	        --> NumberFormatException: Denominator = 0