Keith had 8 1/2 cups of flour. He used 5 2/3 cups to make bread. How many cups of flour does he have left

To solve this you must subtract the two numbers, first you would convert them both to improper fractions (17/2 & 17/3), then you would multiply the numerators and the denominators to have the same denominator. (51/6 & 34/6), Lastly, you would subtract the numerators, and keep the denominators (51-34=17) The answer is 17/6, however, most answers would prefer 2 5/6 (They are the same answer)