If the diameter of a circle increases by 1 cm, by how many cm does its circumference increase? how many centimeters
如果一个圆的直径增加1厘米，那么它的周长就增加多少厘米？多少厘米
<gadget id="calculator">3.14 * 1</gadget>
<output>3.14</output>

<result>3.14</result>