When you multiply a value by 2/3, you are finding 2/3 of that number, so your new length would be 6 and your new width would be 4. The original area was 9 × 6 = 54, and the new area is 6 × 4 = 24. 54 ÷ 24 = 2.25, or 2 1/4, so your answer is 2 1/4, which as an improper fraction is 9/4. I hope this helps!
