The number 1.4 less than 20% of a number is 4.78. Find this number. (solution by equation)
比一个数的20%少1.4的数是4.78，求这个数．(用方程解)
<gadget id="calculator">4.78 + 1.4</gadget>
<output>6.18</output>

<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">6.18 / (1/5)</gadget>
<output>30.9</output>

<result>30.9</result>