To increase the circumference of a circle by 6.28 cm, how many cm should the radius of the circle be increased?
要把一个圆的周长增加6.28厘米，那么这个圆的半径应增加多少厘米．
<gadget id="calculator">6.28 / 3.14 / 2</gadget>
<output>1</output>

<result>1</result>