The diameter of a wheel is 5 decimeters, how many meters does it travel in 3 revolutions?
一个车轮的直径是5分米，转3圈走了多少米．
<gadget id="calculator">3.14 * 5 * 3</gadget>
<output>47.1</output>

<gadget id="calculator">47.1 / 10</gadget>
<output>4.71</output>

<result>4.71</result>