Add 20 grams of sugar to 30 grams of water, what is the sugar content of the sugar water?
在30克的水中加入20克糖，这时糖水的含糖率是多少．
<gadget id="calculator">30 + 20</gadget>
<output>50</output>

<gadget id="calculator">20 / 50</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">100 / 100</gadget>
<output>1</output>

<gadget id="calculator">(2/5) * 1</gadget>
<output>2/5 = around 0.4</output>

<result>2/5 = around 0.4</result>