On a drawing of a precision part with a scale of 50:1, the length of the part is measured to be 40 cm. What is the actual length of this part in millimeters?
在一副比例尺为50：1的精密零件的图纸上，量得零件长40厘米．问这个零件实际长是多少毫米？
<gadget id="calculator">50 / 1</gadget>
<output>50</output>

<gadget id="calculator">40 / 50</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">(4/5) * 10</gadget>
<output>8</output>

<result>8</result>