A precision part is 2.5 mm long. How long should it be drawn with a scale of 20:1?
一种精密零件长2.5毫米，用20：1的比例尺画图，应画多长？
<gadget id="calculator">20 / 1</gadget>
<output>20</output>

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

<gadget id="calculator">2.5 * 2</gadget>
<output>5</output>

<result>5</result>