When calculating an addition problem, he regarded the 8 in the units digit of one addend as 3, and the 2 in the hundreds digit of the other addition as 7, and the result was 909. What is the correct sum?
在计算一道加法题时，他把一个加数个位上的8看成了3，另一个加数百位上的2看成了7，结果得909，正确的和是多少？
<gadget id="calculator">700 - 200</gadget>
<output>500</output>

<gadget id="calculator">909 - 500</gadget>
<output>409</output>

<gadget id="calculator">8 - 3</gadget>
<output>5</output>

<gadget id="calculator">409 + 5</gadget>
<output>414</output>

<result>414</result>