There is a 25cm part on the scale 50:1, what is the actual length of this part in mm?
在比例尺50：1的图上有25cm的零件，这个零件的实际长是多少mm．
<gadget id="calculator">50 / 1</gadget>
<output>50</output>

<gadget id="calculator">25 / 50</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(1/2) * 10</gadget>
<output>5</output>

<result>5</result>