A precision part is drawn on a picture with a scale of 20:1, and its length is 10cm, what is the actual length in mm?
一个精密零件，画在比例尺是20：1的图上，长10cm，则实际长多少mm
<gadget id="calculator">20 / 1</gadget>
<output>20</output>

<gadget id="calculator">10 / 20</gadget>
<output>1/2 = around 0.5</output>

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

<result>5</result>