If the circumference of a circle increases by 0.628 cm, how much does its radius increase in cm?
一个圆的周长增加0.628厘米，那么它的半径增加多少厘米．
<gadget id="calculator">0.628 / 3.14 / 2</gadget>
<output>0.1</output>

<result>0.1</result>