What is the surface area of a cube welded with 30 decimeter wire?
用30分米的铁丝焊成一个正方体，它的表面积是多少．
<gadget id="calculator">30 / 12</gadget>
<output>5/2 = around 2.5</output>

<gadget id="calculator">(5/2) * (5/2) * 6</gadget>
<output>75/2 = around 37.5</output>

<result>75/2 = around 37.5</result>