The price per organic egg is 50 cents. The price of a tray of eggs that contains 30 eggs is $12. How much can you save, in cents, per egg if you buy a tray versus individual eggs?
The price per egg in a tray is $12/30 eggs = $
<gadget id="calculator">12/30</gadget>
<output>2/5 = around 0.4</output>
0.4/egg.
The equivalent of $0.4 in cents is $0.4 x 100 cents/dollar = 
<gadget id="calculator">0.4*100</gadget>
<output>40</output>
40 cents.
Hence, you can save 50 cents - 40 cents = 
<gadget id="calculator">50-40</gadget>
<output>10</output>
10 cents per egg if you buy a tray.

<result>10</result>