If 4 tons of seawater can dry 0.8 tons of salt, how many tons of seawater are needed to dry 400 tons of salt?
如果按4吨海水可以晒盐0.8吨计算，要晒400吨盐，需要多少吨海水．
<gadget id="calculator">4 / 0.8</gadget>
<output>5</output>

<gadget id="calculator">5 * 400</gadget>
<output>2_000</output>

<result>2_000</result>