If the decimal point of a decimal is moved one place to the left, the resulting number is 2.16 less than the original number. What is the decimal number?
一个小数的小数点向左移动一位，得到的数比原数少2.16，这个小数是多少．
<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">2.16 / (9/10)</gadget>
<output>2.4</output>

<result>2.4</result>