Add 20 grams of salt to 1 kilogram of water, what is the percentage of salt in the salt water?
在1千克水中加入20克盐，这时盐占盐水的多少
<gadget id="calculator">1 * 1_000</gadget>
<output>1_000</output>

<gadget id="calculator">1_000 + 20</gadget>
<output>1_020</output>

<gadget id="calculator">20 / 1_020</gadget>
<output>1/51 = around 0.019608</output>

<result>1/51 = around 0.019608</result>