A kind of rapeseed can extract 3.2 kg of rapeseed oil per 10 kg. According to this calculation, how many kilograms of this rapeseed is needed to squeeze out 640 kg of rapeseed oil?
一种油菜籽每10千克可以榨出3.2千克菜油，照这样计算，要榨出640千克的菜油，需要这种油菜籽多少千克？
<gadget id="calculator">640 / 3.2</gadget>
<output>200</output>

<gadget id="calculator">200 * 10</gadget>
<output>2_000</output>

<result>2_000</result>