A square with a side length of 24 cm is exactly formed with a piece of wire. If a rectangle is 30 cm long surrounded by this wire, what is the width of this rectangle in cm?
用一根铁丝正好围成一个边长为24厘米的正方形．如果用这根铁丝围成长是30厘米的长方形，那么这个长方形的宽是多少厘米？
<gadget id="calculator">4 / 2</gadget>
<output>2</output>

<gadget id="calculator">24 * 2</gadget>
<output>48</output>

<gadget id="calculator">48 - 30</gadget>
<output>18</output>

<result>18</result>