A wire 16 decimeters long forms the largest square, what is its area in square decimeters?
把一根长16分米的铁丝围成一个最大的正方形，它的面积是多少平方分米．
<gadget id="calculator">16 / 4</gadget>
<output>4</output>

<gadget id="calculator">4 * 4</gadget>
<output>16</output>

<result>16</result>