When a student is doing addition, he regards the 6 in the ones place of an addend as 3, and the 4 in the tens place as 8. The resulting sum is 123. What should be the correct number?
一个学生在做加法的时候，把一个加数个位上的6看成了3，把十位上的4当作8，结果所得的和是123，原来正确的得数应该是多少．
<gadget id="calculator">6 - 3</gadget>
<output>3</output>

<gadget id="calculator">40 - 3</gadget>
<output>37</output>

<gadget id="calculator">123 - 37</gadget>
<output>86</output>

<result>86</result>