If 100g of sugar water containing 28% sugar is to be converted into sugar water containing 10% sugar, how many grams of water should be added?
100g含糖28%的糖水要变成含糖10%的糖水，需要加水多少克？
<gadget id="calculator">28 / 100</gadget>
<output>7/25 = around 0.28</output>

<gadget id="calculator">10 / 100</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">(7/25) / (1/10)</gadget>
<output>14/5 = around 2.8</output>

<gadget id="calculator">100 * (14/5)</gadget>
<output>280</output>

<gadget id="calculator">280 - 100</gadget>
<output>180</output>

<result>180</result>