After the decimal point of a certain number is moved to the left, it is 40.5 less than the original number. What is the original number?
某数的小数点向左移动一位后，就比原数少40.5，原数是多少？
<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">40.5 / (9/10)</gadget>
<output>45</output>

<result>45</result>