Since Angie has 12 3/4 yards of fabric and all and each costume requires 7/8 yards, you can divide 12 3/4 by 7/8.
12 3/4 ÷ 7/8
= 51/4 ÷ 7/8
= 51/4 • 8/7 (remember that dividing by a fraction is the same thing as multiplying by it’s reciprocal)
= 51/1 • 2/7 (after simplifying)
= 102/7
= 14 4/7
Angie can make 14 costumes. She cannot make the 15th one because she’ll run short of fabric.