A lead wire is 62.8 decimeters long, use it to make two circles of the same size, what is the radius of each circle in decimeters?
一根铅丝长62.8分米，用它做成两个大小相同的圆，每个圆的半径是多少分米．
<gadget id="calculator">62.8 / 2</gadget>
<output>31.4</output>

<gadget id="calculator">31.4 / 3.14 / 2</gadget>
<output>5</output>

<result>5</result>