Standard Addition
Introduction
Apply addition to multi-digit numbers using the standard written algorithm — the method taught in schools worldwide.
The Standard Addition Algorithm
The standard algorithm provides a systematic procedure for adding numbers of any size: 1. Write numbers one above the other, aligned by place value (ones under ones, tens under tens, etc.) 2. Start from the rightmost column (ones). 3. Add all digits in the column, including any carry from the previous column. 4. Write the ones digit of the sum below the column. 5. Carry the tens digit (if any) to the next column. 6. Repeat for each column, moving left.
This method works for 2-digit, 3-digit, 4-digit, or any size numbers.
Quick practice
Using a sample question until this lesson includes practice data. XP sync rolls out with account progress (Phase 4).
Quick warm-up: what is 4 + 3?
For the full tabbed flow with scoring summary, open the Practice tab above.