Solve Vertical Addition: 921 + 79 Step-by-Step

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

• Step 1: Align the numbers vertically by place value.
• Step 2: Add digits in each column starting from the right (units) to the left (hundreds), carrying over if necessary.
• Step 3: Write the final sum at the bottom.

Let's work through the solution:

Step 1: We have the numbers aligned as:

$\begin{aligned} &921 \\ +& \\ &~~79 \\ \end{aligned}$

Step 2: Start adding from the units column:

• Units: $1 + 9 = 10$. Write 0 and carry over 1 to the tens column.
• Tens: $2 + 7 + 1 \text{ (carry over)} = 10$. Write 0 and carry over 1 to the hundreds column.
• Hundreds: $9 + 1 \text{ (carry over)} = 10$. Write 0 and carry over 1 to a new thousands column.
• Thousands: No additional digits to add, so just write 1.

Step 3: Combine the results to obtain the final sum:

The sum is $1000$.

Therefore, the solution to the problem is $1000$.