Use a 24-meter-long iron wire to form a rectangle. If the length of this rectangle is 7 meters, what is the width?
用一根长24米的铁丝围成一个长方形，如果这个长方形的长是7米，宽应该是多少．
<gadget id="calculator">24 / 2</gadget>
<output>12</output>

<gadget id="calculator">12 - 7</gadget>
<output>5</output>

<result>5</result>