A number minus 20% of it equals 200. What is the number?
一个数减去它的20%等于200，这个数是多少？
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (1/5)</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">200 / (4/5)</gadget>
<output>250</output>

<result>250</result>