There are 22 pieces of pizza because 14 plus 8 equals <<14+8=22>>22.
They have eaten 18 pieces of pizza because 9 plus 9 equals <<9+9=18>>18.
There are 4 pieces of pizza left because 22 minus 18 equals <<22-18=4>>4.
There are 2 pieces per person because 4 divided by 2 equals <<4/2=2>>2.
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