Fill in □ so that the solution of the equation □*X+0.4=2 is X=8.
在□里填数，使方程□*X+0.4=2的解是X=8．
<gadget id="calculator">2 - 0.4</gadget>
<output>1.6</output>

<gadget id="calculator">1.6 / 8</gadget>
<output>0.2</output>

<result>0.2</result>