Explaining Code Execution

You're a backend engineer at Interactive Process Technology, working on a batch job that applies discounts to a set of pending orders and prints a run summary to the deploy log. Here is the method your interviewer hands you.

public class DiscountCalculator {
    static int callCount = 0;

    static int applyDiscount(int price) {
        callCount++;
        return price - (price / 10);
    }

    public static void main(String[] args) {
        int[] prices = {50, 99, 100, 250};
        int total = 0;
        int i = 0;

        while (i < prices.length) {
            int discounted = applyDiscount(prices[i]);
            total += discounted;
            i++;
        }

        System.out.println("Processed: " + callCount + " orders");
        System.out.println("Total after discount: $" + total);
        System.out.println("Average order: $" + total / prices.length);
        System.out.println("Message: " + 1 + 2 + " items, " + (1 + 2) + " unique SKUs");
    }
}

Explain exactly what gets printed to the console when this runs, line by line, and explain your reasoning for each line rather than just stating the final numbers.