Solve the Addition Problem: 977 + 23 in Vertical Format

To solve this vertical addition problem, we follow these steps:

• Step 1: Align the numbers for vertical addition:
  $\ \ \ 977$
  $+ 23$
• Step 2: Start by adding the units digits.
  The units digit of $977$ is $7$ and the units digit of $23$ is $3$.
  $7 + 3 = 10$. Write $0$ in the units place and carry over $1$ to the tens place.
• Step 3: Add the tens digits including the carryover.
  The tens digit of $977$ is $7$ and the tens digit of $23$ is $2$.
  Including the carryover $1$:
  $7 + 2 + 1 = 10$. Write $0$ in the tens place and carry over $1$ to the hundreds place.
• Step 4: Add the hundreds digits including the carryover.
  The hundreds digit of $977$ is $9$. There are no hundreds in $23$, so only the carryover $1$ is added:
  $9 + 1 = 10$. Write $0$ in the hundreds place and carry over $1$ to the thousands place.
• Step 5: Since $23$ does not have a thousands place digit, just write the $1$ from the previous carryover in the thousands place.

After completing all these steps, the final sum is $1000$.