For a decimal, if its decimal part is expanded to 4 times its original number, the number is 3.4. If its decimal part is expanded to 9 times its original number, this number is 6.4. What is the original number?
一个小数，如果把它的小数部分扩大到原来的4倍，这个数是3.4，如果把它的小数部分扩大到原来的9倍，这个数是6.4，这个数原来是多少？
<gadget id="calculator">6.4 - 3.4</gadget>
<output>3</output>

<gadget id="calculator">9 - 4</gadget>
<output>5</output>

<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">(3/5) * 4</gadget>
<output>12/5 = around 2.4</output>

<gadget id="calculator">3.4 - (12/5)</gadget>
<output>1</output>

<gadget id="calculator">1 + (3/5)</gadget>
<output>8/5 = around 1.6</output>

<result>8/5 = around 1.6</result>