In 200 grams of salt water with a salt content of 4%, how many grams of salt should be added to obtain a salt water with a salt content of 10%.
在含盐率为4%的200克盐水中，要得到含盐10%的盐水，要加盐多少克．
<gadget id="calculator">4 / 100</gadget>
<output>1/25 = around 0.04</output>

<gadget id="calculator">1 - (1/25)</gadget>
<output>24/25 = around 0.96</output>

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

<gadget id="calculator">1 - (1/10)</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">(24/25) / (9/10)</gadget>
<output>16/15 = around 1.066667</output>

<gadget id="calculator">200 * (16/15)</gadget>
<output>640/3 = around 213.333333</output>

<gadget id="calculator">(640/3) - 200</gadget>
<output>40/3 = around 13.333333</output>

<result>40/3 = around 13.333333</result>