To round to the nearest tens place, look at he value of t he ones. If the ones is a 5 or higher you round the tens value up, if the ones is under 5, the tens value stays the same.
262, the ones is a 2, so the tens stays the same = 260
523, the ones is a 3, so the tens stays the same = 520
Now add: 260 + 520 = 780
The answer is B. 780
