A machine part is 50mm long and drawn on paper at a ratio of 5:1, how many millimeters should be drawn.
一个机器零件长50毫米，按5：1的比例画在纸上，要画多少毫米．
<gadget id="calculator">5 / 1</gadget>
<output>5</output>

<gadget id="calculator">50 * 5</gadget>
<output>250</output>

<result>250</result>