A part with a length of 4mm is drawn on a drawing with a scale of 20:1. What is the length in centimeters?
一个长4毫米的零件，画在比例尺是20：1的图纸上，长多少厘米．
<gadget id="calculator">20 / 1</gadget>
<output>20</output>

<gadget id="calculator">0.4 * 20</gadget>
<output>8</output>

<result>8</result>