Well for the small box of Cornflakes you want to divide $6.30 by 18 and you should get $0.35 which is how much each oz cost.
For the large box you want to convert 2.2 lb to oz, you will get 35.2 oz. Next just do the same divide $8.80 by 35.2 and get $0.25 which is the cost for each oz in the large box.
