Use 6, 4, 0.5 and x to form a ratio and solve the ratio.
用6，4，0.5和x组成比例，并解比例．
<gadget id="calculator">6 / 4</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">0.5 / (3/2)</gadget>
<output>0.333333</output>

<result>0.333333</result>