In 100 grams of salt water with a salt content of 20%, how much salt occupies water
在100克含盐量为20%的盐水中，盐占水的多少
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">100 * (1/5)</gadget>
<output>20</output>

<gadget id="calculator">100 - 20</gadget>
<output>80</output>

<gadget id="calculator">20 / 80</gadget>
<output>1/4 = around 0.25</output>

<result>1/4 = around 0.25</result>