Column calculation: the ratio of 8 and 0.4 is equal to the ratio of 20 and X.
列式计算：8和0.4的比等于20和X的比．
<gadget id="calculator">8 / 0.4</gadget>
<output>20</output>

<gadget id="calculator">20 / 20</gadget>
<output>1</output>

<result>1</result>