On the drawing with a scale of 10:1, the measured length of the part is 40 mm. What is the actual length of the part in mm?
在比例尺是10：1的图纸上，量得零件的长是40毫米，零件的实际长度是多少毫米．
<gadget id="calculator">40 / 10 / 10</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(2/5) * 10</gadget>
<output>4</output>

<result>4</result>