Put 20 grams of salt into 30 grams of water, what percentage of the salt water?
把20克盐放人30克水中，盐占盐水的几分之几？
<gadget id="calculator">20 + 30</gadget>
<output>50</output>

<gadget id="calculator">20 / 50</gadget>
<output>2/5 = around 0.4</output>

<result>2/5 = around 0.4</result>