private void BreakEvenCalculation()
    {
        var purchaseprice = Decimal.Parse(PurchasePriceEntry.Text);
        var purchaseweight = Decimal.Parse(PurchaseWeightEntry.Text);
        var purchasefreight = Decimal.Parse(PurchaseFreightEntry.Text);
        var medicineimplants = Decimal.Parse(MedicineImplantsEntry.Text);
        var costofgain = Decimal.Parse(CostOfGainEntry.Text);
        var poundstillsell = Decimal.Parse(PoundsTillSellEntry.Text);
        var deathloss = Decimal.Parse(DeathLossEntry.Text);
        var saleweight = Decimal.Parse(SaleWeightEntry.Text);
        var salefreight = Decimal.Parse(SaleFreightEntry.Text);
        var breakeven = Decimal.Parse(BreakEvenEntry.Text);


        var purchasedollars = purchaseprice * purchaseweight;
        var feedcost = costofgain * poundstillsell;
        poundstillsell = saleweight - purchaseweight;


        var costs = (purchasedollars + purchasefreight + medicineimplants + feedcost + deathloss + salefreight);
       breakeven = costs / saleweight;             //throws exception.... System.DivideByZeroException: Attempted to divide by zero
        //breakeven = costs / (saleweight + 1);       //correctly equals 1.111302549965541
        //breakeven = costs * saleweight;           //correctly equals 2338125.00
        //breakeven = saleweight;                   //correctly equals 1450.00
        //breakeven = costs;                        //correctly equals 1612.50
        ////////////breakeven should equal  1.112068965517241
        BreakEvenEntry.Text = breakeven.ToString();
    }

breakeven = costs / saleweight;

breakeven = saleweight;