200 grams of water, add 40 grams of salt, how much salt accounts for the salt water.
200克的水，加入40克的盐，盐占盐水的多少．
<gadget id="calculator">200 + 40</gadget>
<output>240</output>

<gadget id="calculator">40 / 240</gadget>
<output>1/6 = around 0.166667</output>

<result>1/6 = around 0.166667</result>