John decides to buy some birds.  He got 50 dollars from each of his 4 grandparents.  If each bird costs $20, how many wings did all the birds have?
He got 4*50=$
<gadget id="calculator">4*50</gadget>
<output>200</output>
200.
That means he was able to buy 200/20=
<gadget id="calculator">200/20</gadget>
<output>10</output>
10 birds.
Since each bird has 2 wings he got 10*2=
<gadget id="calculator">10*2</gadget>
<output>20</output>
20 wings.

<result>20</result>