James is building a hall of mirrors. Three of the walls will be completed covered with glass. If two of those walls are 30 feet by 12 feet and the third is 20 feet by 12 feet, how many square feet of glass does he need?
First find the area of one of the long walls: 30 feet * 12 feet = 
<gadget id="calculator">30*12</gadget>
<output>360</output>
360 square feet.
Then double that amount since there are two walls: 360 square feet * 2 = 
<gadget id="calculator">360*2</gadget>
<output>720</output>
720 square feet.
Then find the area of the short wall: 20 feet * 12 feet = 
<gadget id="calculator">20*12</gadget>
<output>240</output>
240 square feet.
Then add that area to the area of the two long walls to find the total area: 720 square feet + 240 square feet = 
<gadget id="calculator">720+240</gadget>
<output>960</output>
960 square feet.

<result>960</result>