Prepare a kind of salt water, the weight ratio of salt and water is 1:2, and the salt is the weight of the salt water.
配制一种盐水，盐和水的重量比是1：2，盐是盐水重量的多少．
<gadget id="calculator">1 + 2</gadget>
<output>3</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<result>1/3 = around 0.333333</result>