After the decimal point of a decimal is moved one place to the right, it is 8.1 larger than the original number. What is the number?
一个小数的小数点向右移动一位后，比原数大8.1，这个数是多少．
<gadget id="calculator">10 - 1</gadget>
<output>9</output>

<gadget id="calculator">8.1 / 9</gadget>
<output>0.9</output>

<result>0.9</result>