The weight of a pack of washing powder is 500 grams, how many kilograms are 4 packs of such washing powder?
一包冼衣粉的重量是500克，4包这样的洗衣粉是多少千克．
<gadget id="calculator">4 / 1_000</gadget>
<output>1/250 = around 0.004</output>

<gadget id="calculator">500 * (1/250)</gadget>
<output>2</output>

<result>2</result>