The diameter of a wheel is 50 centimeters, how many meters does the wheel travel 4 times?
一个车轮的直径是50厘米，车轮转动4周，前进多少米．
<gadget id="calculator">3.14 * 50 * 4</gadget>
<output>628</output>

<gadget id="calculator">628 / 100</gadget>
<output>157/25 = around 6.28</output>

<result>157/25 = around 6.28</result>