The width of a rectangle is 4 cm, the circumference is 6 times the width, what is the length?
一个长方形的宽是4厘米，周长是宽的6倍，长是多少．
<gadget id="calculator">4 * 6</gadget>
<output>24</output>

<gadget id="calculator">24 / 2</gadget>
<output>12</output>

<gadget id="calculator">12 - 4</gadget>
<output>8</output>

<result>8</result>