Solve Three-Digit Addition: 281 + 507 in Vertical Format

To solve this problem, we'll perform vertical addition as follows:

• Step 1: Align the numbers by columns (units, tens, hundreds).
  $\begin{aligned} &281 \\ +& \\ &507 \\ \hline \end{aligned}$

• Step 2: Add the digits from the rightmost column to the leftmost:
  - Units place: Add 1 and 7, which equals 8. No carry is needed here.
  - Tens place: Add 8 and 0, which equals 8. No carry is needed here.
  - Hundreds place: Add 2 and 5, which equals 7. No carry is needed here.

Therefore, the sum of $281$ and $507$ is $788$.

The solution to the problem is $788$.