Long subtraction is the standard algorithm for subtracting multi-digit numbers. It processes digits column by column from right to left, borrowing when necessary.

Steps:

1. Align the numbers by place value (ones, tens, hundreds, etc.)
2. Start with the rightmost column (ones place)
3. If the top digit is larger than or equal to the bottom digit, subtract normally
4. If the top digit is smaller, borrow 1 from the next column to the left
5. Add 10 to the current top digit, then subtract
6. Remember to subtract 1 from the column you borrowed from
7. Continue until all columns are processed

Example: 542 - 267

Step-by-step breakdown:

• Ones place: 2 < 7, so borrow 1 from tens: 12 - 7 = 5
• Tens place: 4 - 1 (borrowed) = 3, then 3 < 6, so borrow 1 from hundreds: 13 - 6 = 7
• Hundreds place: 5 - 1 (borrowed) = 4, then 4 - 2 = 2
• Result: 275

Checking your work: Add the result to the subtrahend. This should equal the original minuend: 275 + 267 = 542 ✓