Richard has already baked 12 pies and he bakes 1 pie with each additional cup of sugar he buys. How many additional cups of sugar does he need to bake 27pies
If each pie has 1 cup of sugar, then you need 12 cups of sugar to make 12 pies. So, if there are 27 pies and 27 cups of sugar, then you subtract 12 from 27.
