queue in shop

internal class Program
{
    static void Main(string[] args)
    {
        int accountBalance = 0;
        Queue<int> purchaseAmounts = new Queue<int>();

        FillQueue(purchaseAmounts);
        accountBalance = ServeClients(purchaseAmounts);
        Console.WriteLine($"На счете - {accountBalance}");
    }

    static void FillQueue(Queue<int> queue)
    {
        bool isNumber = false;
        int numbersOfValues = 0;

        while (isNumber == false)
        {
            Console.Write("Сколько значений собираетесь ввести?: ");
            isNumber = ChekNumber(out numbersOfValues);

            if (isNumber == false)
            {
                Console.WriteLine("Вы ввели не число.");
                Console.ReadKey();
            }
            Console.Clear();
        }

        for (int i = 0; i < numbersOfValues; i++)
        {
            Console.Write($"Введите значение: ");
            isNumber = ChekNumber(out int value);

            if (isNumber == true)
            {
                queue.Enqueue(value);
            }
            else
            {
                Console.WriteLine("Вы ввели не число.");
                i--;
                Console.ReadKey();
            }
            Console.Clear();
        }
    }

    static int ServeClients(Queue<int> queue)
    {
        int totalValues = 0;

        while(queue.Count > 0 )
        {
            totalValues += queue.Dequeue();
            Console.WriteLine($"Сумма = {totalValues}");
            Console.ReadKey();
            Console.Clear();
        }

        return totalValues;
    }

    static bool ChekNumber (out int number)
    {
        bool isNumber = int.TryParse(Console.ReadLine(), out number);
        return isNumber;
    }
}