The circumference of the circle is reduced from 15.7cm to 9.42cm, and its radius is reduced by how many centimeters.
圆的周长从15.7cm减少到9.42cm，它的半径比原来减少了多少cm．
<gadget id="calculator">15.7 - 9.42</gadget>
<output>6.28</output>

<gadget id="calculator">2 * 3.14</gadget>
<output>6.28</output>

<gadget id="calculator">6.28 / 6.28</gadget>
<output>1</output>

<result>1</result>