How many grams of water should be added to dilute 500 grams of 8% salt water into 5% salt water?
把食盐8%的盐水500克，稀释成含盐5%的盐水，要加水多少克？
<gadget id="calculator">8 / 100</gadget>
<output>2/25 = around 0.08</output>

<gadget id="calculator">500 * (2/25)</gadget>
<output>40</output>

<gadget id="calculator">5 / 100</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">40 / (1/20)</gadget>
<output>800</output>

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

<result>300</result>