On a drawing with a scale of 50:1, the length of a precision part on the drawing is 40 cm. What is the actual length of this part in millimeters?
在比例尺是50：1的图纸上，一种精密零件的图上长度是40厘米，则这种零件的实际长度是多少毫米．
<gadget id="calculator">50 / 1</gadget>
<output>50</output>

<gadget id="calculator">10 / 50</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">40 * (1/5)</gadget>
<output>8</output>

<result>8</result>