Solve Two-Digit Addition: 52 + 39 in Vertical Format

$\begin{aligned} &52 \\ +& \\ &39 \\ &\underline{\phantom{776}} & \\ \end{aligned}$

To solve this problem, we'll follow these steps:

• Step 1: Align the numbers 52 and 39 for vertical addition.
• Step 2: Add the ones place digits: 2 + 9.
• Step 3: Handle any carry if needed and proceed to the tens place: 5 + 3.

Let's work through each step:

Step 1: Write the numbers in vertical alignment:

$\begin{array}{c} 52 \\ +39 \\\hline \end{array}$

Step 2: Add the digits in the ones column (rightmost):

$2 + 9 = 11$. Since this is more than 9, write 1 in the ones place and carry over 1 to the tens place.

Step 3: Add the digits in the tens place:

Including the carried over 1 from the ones addition, add $5 + 3 + 1 = 9$.

Write 9 in the tens place.

Therefore, the sum of $52 + 39$ is $91$.

Thus, the correct solution to the problem is 91.