After the decimal point of a decimal is moved one place to the right, the number obtained is 9.9 greater than the original number. What is the original number?
一个小数的小数点向右移动一位后，得到的数比原数大9.9，原数是多少．
<gadget id="calculator">10 - 1</gadget>
<output>9</output>

<gadget id="calculator">9.9 / 9</gadget>
<output>1.1</output>

<result>1.1</result>