Solution instead of writing a bunch of if's (Java)

I am trying to write code to let the user pick addition, subtraction, multiplication or division. Once the user has picked one, the program will ask them what difficulty they want, etc... Instead of writing something like :

   if (operation.equals("1") || operation.equals("addition")){
            if(level.equals("1")) {

            } else if (level.equals("2")){

            }

        } else if (operation.equals("2") || operation.equals("subtraction")) {
            if(level.equals("1")) {

            } else if (level.equals("2")){

            }
        } else if (operation.equals("3") || operation.equals("multiplication")) {
            if(level.equals("1")) {

            } else if (level.equals("2")){

            }
        } else if (operation.equals("4") || operation.equals("division")) {
            if(level.equals("1")) {

            } else if (level.equals("2")){

            }
        }

And so on... Is there an easier way to write something like this? Instead of writing a bunch of if statements?