Addieren: $num1 + $num2 = $resAdd
Subtrahieren: $num1 - $num2 = $resSub
Multiplizieren: $num1 * $num2 = $resMul
Dividieren: $num1 / $num2 = $resDiv
Modulo: $num1 % $num2 = $resMod
Summe: $sum