Careless, when calculating an addition problem, he regards the 7 in the ones place of an addend as 1, and the 3 in the tens place as 8, and the result is 342. What is the correct sum?
小粗心在计算一道加法题时，把一个加数个位上的7看作1，十位上的3看作8，结果为342．正确的和是多少？
<gadget id="calculator">342 - 81</gadget>
<output>261</output>

<gadget id="calculator">261 + 37</gadget>
<output>298</output>

<result>298</result>