The two inner terms of the ratio are 5 and 3.6, and the two outer terms are x and 6.
比例的两个内项分别是5和3.6，两个外项分别是x和6．
<gadget id="calculator">5 * 3.6</gadget>
<output>18</output>

<gadget id="calculator">18 / 6</gadget>
<output>3</output>

<result>3</result>