If 10 grams of sugar is used to prepare sugar water with a sugar content of 20%, how many grams of water should be added?
用10克糖配制成含糖率为20%的糖水，需加水多少克？
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">10 / (1/5)</gadget>
<output>50</output>

<gadget id="calculator">50 - 10</gadget>
<output>40</output>

<result>40</result>