To find the answer to this problem, all you have to do is divide the price of the product by the number of ounces. So to find the price per ounce of the large can of tomato soup, you divide 4.40 by 22, which equals .20 cents per ounce. For the smaller can, you divide 1.80 by 10, which equals .18 cents per ounce. So the smaller can has the best price per ounce.