Xiaodong used some money to buy pencils. If you buy 6 pieces, then there will be 0.6 yuan left; if you buy 9 pieces, then there will be a difference of 3.9 yuan. How much is Xiao Dongyuan?
小东用一些钱买铅笔．如果买6支，那么就余0.6元；如果买9支，那么还差3.9元．小东原有多少元？
<gadget id="calculator">0.6 + 3.9</gadget>
<output>4.5</output>

<gadget id="calculator">4.5 / 3</gadget>
<output>1.5</output>

<gadget id="calculator">6 * 1.5</gadget>
<output>9</output>

<gadget id="calculator">9 + 0.6</gadget>
<output>9.6</output>

<result>9.6</result>