Can't Create A New Method Or Use Case Statements

I'm trying to create a simple java math question quiz using random operators, but keep sinking myself into deeper despair. The numbers must range from 0-9 and given an operator: +,-,/,*,%. Can't create a new method or use Case statements. The code isn't finished but don't want to make it any worse.

package marco;
import java.util.Scanner;
import java.util.Random;
public class Project {
public static void main(String[] args) {
Scanner keyboard = new Scanner(System.in);
Random rand = new Random();
System.out.println("How many questions do you want?");

[code]...