A kind of pesticide is prepared by mixing medicine and water according to the ratio of 1:500. If there are 25 kilograms of medicine liquid, how many kilograms of water is needed.
一种农药，用药和水按照1：500配制而成，现有25千克药液，则需用水多少千克．
<gadget id="calculator">25 / 1</gadget>
<output>25</output>

<gadget id="calculator">25 * 500</gadget>
<output>12_500</output>

<result>12_500</result>