The difference between 40% of a number minus 4 is 6. Find this number.
一个数的40%减4差是6，求这个数．
<gadget id="calculator">6 + 4</gadget>
<output>10</output>

<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">10 / (2/5)</gadget>
<output>25</output>

<result>25</result>