When the little sloppy calculated an addition problem, he regarded the "5" in the tens place as "8", and the result was 648. What should be the correct answer.
小马虎在计算一道加法题时，把十位上的"5"看成了"8"，结果是648．正确的答案应是多少．
<gadget id="calculator">648 - 30</gadget>
<output>618</output>

<result>618</result>