Dynamic Grid From User Input

import java.util.Scanner;
import java.util.Arrays;

public class Question3
{
    private static String[][] grid = new String[3][3];

    public static void main(String[] args)
    {
        Scanner sourceValues = new Scanner(System.in);

        String A1, B1, C1, A2, B2, C2, A3, B3, C3;

        A1 = sourceValues.next();
        B1 = sourceValues.next();
        C1 = sourceValues.next();
        A2 = sourceValues.next();
        B2 = sourceValues.next();
        C2 = sourceValues.next();
        A3 = sourceValues.next();
        B3 = sourceValues.next();
        C3 = sourceValues.next();

        grid[0] = new String[]{A1, B1, C1};
        grid[1] = new String[]{A2, B2, C2};
        grid[2] = new String[]{A3, B3, C3};

        for (int i=0; i<3; i++)
        {
            for (int j=0; j<3; j++)
            {
                if (grid[i][j].startsWith("="))
                {
                    grid[i][j] = evaluate(grid[i][j]);
                }
            }
        }

        for (int i=0; i<3; i++)
        {
            for (int j=0; j<3; j++)
            {
                System.out.print(grid[i][j] + " ");
            }
        System.out.println();
        }
    }

    public static String evaluate(String value)
    {
        int total;
        if (value.length() > 3)
        {
            total = returnGridValue(value.substring(0,3));
        }
        else
        {
            total = returnGridValue(value.substring(0));
        }
        for (int t=3; t < value.length(); t += 3)
        {
            if (Character.toString(value.charAt(3)).equals("+"))
                total += returnGridValue(value.substring(t+1,t+3));
            else
                total -= returnGridValue(value.substring(t+1));
        }
        return String.valueOf(total);
    }

    public static int returnGridValue(String coords)
    {
        if (coords.startsWith("=")){
            coords = coords.substring(1);}
        String valueAtCoords;
        switch (coords) {
            case "A1":
                valueAtCoords = grid[0][0];
                break;
            case "B1":
                valueAtCoords = grid[0][1];
                break;
            case "C1":
                valueAtCoords = grid[0][2];
                break;
            case "A2":
                valueAtCoords = grid[1][0];
                break;
            case "B2":
                valueAtCoords = grid[1][1];
                break;
            case "C2":
                valueAtCoords = grid[1][2];
                break;
            case "A3":
                valueAtCoords = grid[2][0];
                break;
            case "B3":
                valueAtCoords = grid[2][1];
                break;
            default:
                valueAtCoords = grid[2][2];
                break;
        }
        int intValueAtCoords = Integer.parseInt(valueAtCoords);
        return intValueAtCoords;
    }
}