((0.4)/(x))=(8/21).
((0.4)/(x))=(8/21)．
<gadget id="calculator">8 / 21</gadget>
<output>8/21 = around 0.380952</output>

<gadget id="calculator">0.4 / (8/21)</gadget>
<output>1.05</output>

<result>1.05</result>