Alice had 10/12 yard of fabric. She used 8/12 for a pillow. How much fabric did she have left? Explain how you found your answer.

Alice has 2/12, or 1/6 yards of fabric left. I found my answer because since 10/12 and 8/12 have the same denominator, I can subtract without finding a common denominator. 10 - 8 is 2, so the answer is 2/12, or 1/6.