80% of the number A is the number B, and 20% of the number B is 16. What is the number A?
甲数的80%是乙数，乙数的20%是16，甲数是多少？
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">16 / (1/5) / (4/5)</gadget>
<output>100</output>

<result>100</result>