After removing the decimal point, a one-digit number is 21.6 more than the original number. What is the original number?
一个一位小数去掉小数点后，比原数增加了21.6，原来的小数是多少．
<gadget id="calculator">10 - 1</gadget>
<output>9</output>

<gadget id="calculator">21.6 / 9</gadget>
<output>2.4</output>

<result>2.4</result>