Take a piece of square paper with a side length of 6.28 decimeters and roll it into the largest paper tube. What is the radius of the bottom surface of the paper tube in decimeters?
用一张边长是6.28分米的正方形纸，卷成一个最大的纸筒，纸筒的底面半径是多少分米．
<gadget id="calculator">6.28 / 3.14 / 2</gadget>
<output>1</output>

<result>1</result>