John invited 20 people to a birthday party.  Each guest will eat 2 hot dogs.  He already has 4 hot dogs left over from a previous party.  If a pack of hot dogs contains 6 hot dogs and costs $2, how much does he need to spend on hot dogs?
He needs 2*20=
<gadget id="calculator">2*20</gadget>
<output>40</output>
40 hot dogs.
So he needs another 40-4=
<gadget id="calculator">40-4</gadget>
<output>36</output>
36 hot dogs.
So he needs to buy 36/6=
<gadget id="calculator">36/6</gadget>
<output>6</output>
6 packs of hotdogs.
That means he needs to spend 6*2=$
<gadget id="calculator">6*2</gadget>
<output>12</output>
12.

<result>12</result>