Random Chunk Selctor

package personthecat.seededchunkmatcher;

import java.util.Arrays;
import java.util.Random;

public class Main
{
    static Random rand = new Random(12345);

    public static void main(String[] args)
    {
        int[][] coordinates = new int[][]

            {{0, 1, 2, 3, 4, 5, 6, 7, 8, 9},
             {0, 1, 2, 3, 4, 5, 6, 7, 8, 9},
             {0, 1, 2, 3, 4, 5, 6, 7, 8, 9},
             {0, 1, 2, 3, 4, 5, 6, 7, 8, 9},
             {0, 1, 2, 3, 4, 5, 6, 7, 8, 9},
             {0, 1, 2, 3, 4, 5, 6, 7, 8, 9},
             {0, 1, 2, 3, 4, 5, 6, 7, 8, 9},
             {0, 1, 2, 3, 4, 5, 6, 7, 8, 9},
             {0, 1, 2, 3, 4, 5, 6, 7, 8, 9},
             {0, 1, 2, 3, 4, 5, 6, 7, 8, 9}};

        boolean[][] matches = new boolean[10][10];

        int ID = getNumberForName("iron_ore");

        System.out.println("Name ID: " + ID);

        for (int x = 0; x < coordinates.length; x++)
        {
            for (int y = 0; y < coordinates[0].length; y++)
            {
                int concatenatedValues = concatenateNumbers(ID, x, y);

                matches[x][y] = (((double) rand.nextInt(concatenatedValues) / (double) concatenatedValues) > 0.75);
            }
        }

        for (int x = 0; x < matches.length; x++)
        {
            System.out.println(Arrays.toString(matches[x]));
        }
    }

    /*
     * Could concatenate these numbers to produce a more unique
     * value of every string. It's easier for me to work with
     * smaller numbers, however.
     */
    private static int getNumberForName(String name)
    {
        int number = 0;

        for (Character c : name.toCharArray())
        {
            number += Character.getNumericValue(c);
        }

        return number;
    }

    private static int concatenateNumbers(int... numbers)
    {
        StringBuilder sb = new StringBuilder(numbers.length);

        for (int number : numbers)
        {
            sb.append(Math.abs(number));
        }

        return Integer.valueOf(sb.toString());
    }
}