After moving the decimal point of a number one place to the left, the number obtained is 13.5 smaller than the original number. What is the original number?
把一个数的小数点向左移动一位后，得到的数比原来小13.5，这个数原来是多少？
<gadget id="calculator">1 - 0.1</gadget>
<output>0.9</output>

<gadget id="calculator">13.5 / 0.9</gadget>
<output>15</output>

<result>15</result>