Adding a 0 to the end of the denominator of a true fraction reduces the original number by (18/25). What is the original number?
一个真分数的分母末尾添上一个0，比原数减少了(18/25)，原数是多少．
<gadget id="calculator">18 / 25</gadget>
<output>18/25 = around 0.72</output>

<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">1 - (1/10)</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">(18/25) / (9/10)</gadget>
<output>4/5 = around 0.8</output>

<result>4/5 = around 0.8</result>