Put 30 grams of salt into 70 grams of water, what is the percentage of salt in the salt water?
把30克盐放入70克水中，盐占盐水的多少．
<gadget id="calculator">30 + 70</gadget>
<output>100</output>

<gadget id="calculator">30 / 100</gadget>
<output>3/10 = around 0.3</output>

<result>3/10 = around 0.3</result>