For a one-digit decimal, expand its decimal part to 2 times the original number, which is 8.8, and expand its decimal part to 5 times the original number, and this number is 11.5. What was the original number?
一个一位小数，把它的小数部分扩大到原来的2倍，这个数是8.8，把它的小数部分扩大到原来的5倍，这个数是11.5．这个数原来是多少？
<gadget id="calculator">11.5 - 8.8</gadget>
<output>2.7</output>

<gadget id="calculator">5 - 2</gadget>
<output>3</output>

<gadget id="calculator">2.7 / 3</gadget>
<output>0.9</output>

<gadget id="calculator">0.9 * 2</gadget>
<output>1.8</output>

<gadget id="calculator">8.8 - 1.8</gadget>
<output>7</output>

<gadget id="calculator">7 + 0.9</gadget>
<output>7.9</output>

<result>7.9</result>