Dean ordered 2 large pizzas that were each cut into 12 slices.  His friends Frank and Sammy came over to enjoy some pizza and watch a movie.  Dean was hungry and ate half of the Hawaiian pizza.  Frank only ate 3 slices of Hawaiian pizza and Sammy ate a third of the cheese pizza.  How many total slices were left over?
2 pizzas were ordered and had 12 slices each for a total of 2*12 = 
<gadget id="calculator">2*12</gadget>
<output>24</output>
24 slices.
Dean ate 1/2 of a 12 sliced pizza so 12/2 = 
<gadget id="calculator">12/2</gadget>
<output>6</output>
6 slices were left over.
Sammy ate 1/3 of a 12 sliced pizza so 12/3 = 
<gadget id="calculator">12/3</gadget>
<output>4</output>
4 slices were left over.
Dean ate 6 slices, Sammy ate 4 and Frank had 3 so 6+4+3 = 
<gadget id="calculator">6+4+3</gadget>
<output>13</output>
13.
They started with 24 slices and 13 slices so 24-13 = 
<gadget id="calculator">24-13</gadget>
<output>11</output>
11 slices left.

<result>11</result>