The scale of a drawing is 30:1, which means the actual distance is ((())/(())) of the distance on the drawing.
一幅图纸的比例尺是30：1，它表示实际距离是图上距离的((())/(()))．
<gadget id="calculator">1 / 30</gadget>
<output>1/30 = around 0.033333</output>

<result>1/30 = around 0.033333</result>