Long addition is the standard algorithm for adding multi-digit numbers. It processes digits from right to left, handling carries as needed.

Steps:

1. Align the numbers by place value (ones, tens, hundreds, etc.)
2. Start with the rightmost column (ones place)
3. Add all digits in that column
4. If the sum is 10 or greater, write the ones digit and carry the tens digit
5. Move to the next column and repeat, including any carry
6. Continue until all columns are processed

Example: 567 + 489

• Ones: 7 + 9 = 16 → write 6, carry 1
• Tens: 6 + 8 + 1 = 15 → write 5, carry 1
• Hundreds: 5 + 4 + 1 = 10 → write 0, carry 1
• Thousands: 0 + 0 + 1 = 1 → write 1