A potion is prepared by mixing liquid medicine and water at a ratio of 1:1000. The existing liquid medicine is 5 kg, how many kg of water should be added.
一种药水是由药液和水按1：1000配制而成的．现有药液5千克，应加水多少千克．
<gadget id="calculator">1 / 1_000</gadget>
<output>1/1_000 = around 0.001</output>

<gadget id="calculator">5 / (1/1_000)</gadget>
<output>5_000</output>

<result>5_000</result>