program Welcome;
uses
WinCrt;
var a,b,Sum,Sub,Multi,Divi,i:integer;
begin
repeat
Writeln('Plaese select a operator : 1= Sum 2= Subtraction 3= Multiplication 4= Division 5 = Exit');
readln(i);
case i of
1:
begin
Writeln('Please enter 2 number for sum :');
readln(a,b);
Sum=a+b;
writeln('Sum...