A 80 cm long iron wire is folded into a 30 cm long rectangle, what is the width of this rectangle in cm?
用一根长80厘米的铁丝折成一个长30厘米的长方形，这个长方形的宽是多少厘米？
<gadget id="calculator">80 / 2</gadget>
<output>40</output>

<gadget id="calculator">40 - 30</gadget>
<output>10</output>

<result>10</result>