For a decimal, if you move the decimal point one bit to the right, the resulting number is 4.5 more than the original number. What is the original number.
一个小数，如果把他的小数点向右移动一位，得到的数比原数多4.5．原来这个小数是多少．
<gadget id="calculator">10 - 1</gadget>
<output>9</output>

<gadget id="calculator">4.5 / 9</gadget>
<output>0.5</output>

<result>0.5</result>