Use a 16dm long iron wire to make a circular iron ring, the joint is 0.3dm, what is the diameter of this iron ring in dm?
用一根长16dm的铁丝做一个圆形铁圈，接头处是0.3dm，这个铁圈的直径是多少dm？
<gadget id="calculator">16 - 0.3</gadget>
<output>15.7</output>

<gadget id="calculator">15.7 / 3.14</gadget>
<output>5</output>

<result>5</result>