How to get rid of an overflow in my code?

I needed to create a code that inputs 4 numbers and outputs the product and average of these numbers. I needed to output them both as integers and decimals. However, to compute the product the second time (with decimals) I am supposed to input values like 100000, 200000, 300000, 500000, which causes an overflow and I'm not sure how to fix it. Thank you!

Here is my code:

import java.util.Scanner;

public class LabProgram {
   public static void main(String[] args) {
      Scanner scnr = new Scanner(System.in);
      int num1;
      int num2;
      int num3;
      int num4;
      double numProduct;
      double numAverage;
  
      num1 = scnr.nextInt();
      num2 = scnr.nextInt();
      num3 = scnr.nextInt();
      num4 = scnr.nextInt();
      numProduct = num1 * num2 * num3 * num4;
      numAverage = (num1 + num2 + num3 + num4) * 0.25;
  
      System.out.print((int)numProduct + " ");
      System.out.println((int)numAverage);
      System.out.printf("%.3f ", numProduct);
      System.out.printf("%.3f", numAverage);
   }
}

Manually casting the first num1 in your mulitplication will do it.

numProduct = (double) num1 * num2 * num3 * num4;

The problem was that the multiplication of the 4 ints is done in int, and then the final result is cast into a double on assignment to numProduct. You need to cast the first int into a double in the multiplication in order to force whole multiplication to be done in double.