Say instead you cut the pizza into smaller pieces. How about cutting the whole pizza pie into 12 equal pieces? Each of five people takes one piece or 1/12 of the pie. Each piece is very small, much smaller than 1/6 of the pie or 1/4 of the pie. 5 of the 12 pieces or as a fraction 5/12 are gone. How many are left? 12 pieces minus 5 pizza slices equals 7 pieces left. Now 7 of 12 pieces pizza are left in your pie; that can be written as a fraction, too: 7/12.