20 grams of medicinal powder is dissolved in 80 grams of water, how much medicinal powder accounts for the liquid medicine.
20克药粉溶于80克水中，药粉占药水的多少．
<gadget id="calculator">20 + 80</gadget>
<output>100</output>

<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<result>1/5 = around 0.2</result>