Answer 1

It’s not that hard at all,
you get user input of 2 numbers and which operator to do (+, -, /, *)
and then give them the result,
a simple example (C#)

public void main()
{
int x;
int y;
string op;

while(true)
{
Console.WriteLine(“num: “)
x = int.parse(Console.ReadLine());
Console.WriteLine(“num2: “)
y = int.Parse(Console.ReadLine());
Console.WriteLine(“operator: “)
op = Console.ReadLine();
Console.WriteLine(calc(x, y, op);

}
}
private double calc(int x, int y, string op)
{
int res;
switch(op)
{
case “+”:
res = x + y;
break;

case “-“:
res = x - y;
break;

case “/“:
res = x / y;
break;

case “*”:
res = x * y;
break;
}
return res;
}

Answer 2

In what language.