Kurt's old refrigerator cost $0.85 a day in electricity.  He recently bought a new energy-efficient refrigerator that only cost $0.45 a day in electricity.  How much money does Kurt save in a 30-day month with his new refrigerator?
The old refrigerator costs $0.85 a day so for 30 days it costs .85*30 = $
<gadget id="calculator">0.85*30</gadget>
<output>25.5</output>
25.50.
The new refrigerator costs $0.45 a day so for 30 days it costs .45*30 =$
<gadget id="calculator">0.45*30</gadget>
<output>13.5</output>
13.50.
Over 30 days, Kurt saves 25.50-13.50 = $
<gadget id="calculator">25.50-13.50</gadget>
<output>12</output>
12.00 a month with his new refrigerator.

<result>12</result>