Solve Three-Digit Addition: 877 + 656 in Vertical Format

$\begin{aligned} &877 \\ +& \\ &656 \\ &\underline{\phantom{776}} & \\ \end{aligned}$

To solve this problem, we will perform the addition of the numbers 877 and 656 using the vertical column method. Let's break it down step by step:

• Step 1: Write the numbers vertically aligned by their place values: units, tens, and hundreds.
• Step 2: Start by adding the units column (rightmost column): $7 + 6 = 13$. Write down 3 in the units place and carry over 1 to the tens place.
• Step 3: Next, add the tens column: $7 + 5 = 12$. Adding the carryover 1 gives total $13$. Write down 3 in the tens place and carry over 1 to the hundreds place.
• Step 4: Finally, add the hundreds column: $8 + 6 = 14$. Adding the carryover 1 gives total $15$. Since this is the leftmost column, write down the entire result, 15, in the appropriate place.

The sum of the numbers is therefore $1533$.

Hence, the correct answer to the problem is $1533$.