public void GetCartTotals() { var cartTotal = 0.0; var taxTotal = 0.0; var totalItemPrice = 0.0; foreach (var product in Products) { _taxCalculator.SetProductTax(product); _salesPriceCalculator.CalculateItemTotalWithTax(product); taxTotal += (double)product.ItemTaxAmount; totalItemPrice += (double)product.BasePrice; cartTotal += (double)product.TotalWithTax; } TotalItemPrice = (decimal)totalItemPrice; TotalTax = (decimal)Math.Ceiling(taxTotal * 20) / 20; CartTotal = (decimal)cartTotal; }