the drop down options are the same for every box

Mackler, Inc. sells a product with a contribution margin of $50 per unit. Fixed costs are $8,000 per month. How many units must Mackler sell to break even? Begin by showing the formula and then entering the amounts to calculate the units Mackler must sell to break even. (Abbreviation used: CM contribution margin Complete all input boxes. Enter a "O" for items with a zero value) - Required sales in units CM per unit CM ratio Fixed costs Variable costs