The extraction rate of a kind of flour is 80%, how many kilograms of wheat are needed to get 320 kilograms of flour?
一种面粉的出粉率是80%，要得到320千克面粉，需要多少千克小麦？
<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">320 / (4/5)</gadget>
<output>400</output>

<result>400</result>