Put 10 grams of sugar in a glass of water, and then pour 200 grams of 5% sugar water to make 2% sugar water. How much water is there in the glass?
一杯水中放入10克糖，再倒入浓度为5%的糖水200克，配成浓度为2%的糖水，问原来杯中有多少水？
<gadget id="calculator">5 / 100</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">200 * (1/20)</gadget>
<output>10</output>

<gadget id="calculator">10 + 10</gadget>
<output>20</output>

<gadget id="calculator">2 / 100</gadget>
<output>1/50 = around 0.02</output>

<gadget id="calculator">20 / (1/50)</gadget>
<output>1_000</output>

<gadget id="calculator">1_000 - 200 - 10</gadget>
<output>790</output>

<result>790</result>