Add 300 grams of water to 500 grams of salt water containing 8% salt, what percentage of salt is the current salt water?
在含盐8%的500克盐水中加入300克水，现在的盐水含盐百分之几？
<gadget id="calculator">8 / 100</gadget>
<output>2/25 = around 0.08</output>

<gadget id="calculator">500 + 300</gadget>
<output>800</output>

<gadget id="calculator">(2/25) / 800</gadget>
<output>1/10_000 = around 0.0001</output>

<gadget id="calculator">500 * (1/10_000)</gadget>
<output>1/20 = around 0.05</output>

<result>1/20 = around 0.05</result>