Solve Three-Digit Addition: 543 + 457 in Vertical Format

$\begin{aligned} &543\\ +& \\ &457 \\ &\underline{\phantom{776}} & \\ \end{aligned}$

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

• Add the digits in the units place (rightmost).
• Add the digits in the tens place, including any carry from the units place.
• Add the digits in the hundreds place, including any carry from the tens place.

Let's work through the addition step-by-step:

Step 1: Add the Units Place
The units digits are 3 and 7. Adding these gives $3 + 7 = 10$.
Write 0 in the units place of the answer and carry over the 1 to the tens column.

Step 2: Add the Tens Place
The tens digits are 4 and 5, plus the carryover 1. Adding these gives $4 + 5 + 1 = 10$.
Write 0 in the tens place of the answer and carry over the 1 to the hundreds column.

Step 3: Add the Hundreds Place
The hundreds digits are 5 and 4, plus the carryover 1. Adding these gives $5 + 4 + 1 = 10$.
This gives us 10 in the hundreds and thousands places.

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