Програма-калькулятор:
program cal;
var a,b: integer;
c: char;
d: real;
begin
writeln ('vvedit dva chisla');
readln (a,b);
writeln ('vvedit znak');
readln (c);
case c of
'+': d:=a+b;
'-': d:=a-b;
'*': d:=a*b;
'/': if b=0 then writeln ('na 0 delit nemojna')
else d:=a/b;
else writeln ('ne virnui znak');
end;
writeln (a,c,b,'=',d:6:3);
readln
end.