Arithmetic Operations
Multi-Digit Addition
Once you can add two-digit numbers with carrying, the same method extends perfectly to any number of digits. The process never changes — you simply have more columns to work through.
Three-Digit Addition
¹ ¹ 4 5 6 + 3 8 7 ------- 8 4 3
Ones: 6+7=13 → 3 carry 1. Tens: 5+8+1=14 → 4 carry 1. Hundreds: 4+3+1=8. Answer: 843
Four-Digit Addition
¹ ¹
3 7 4 2
+ 1 5 8 9
---------
5 3 3 1
Ones: 2+9=11 → 1 carry 1. Tens: 4+8+1=13 → 3 carry 1. Hundreds: 7+5+1=13 → 3 carry 1. Thousands: 3+1+1=5. Answer: 5,331
Try It Yourself: 3,742 + 1,589
Press each step below (or use Auto Play) to work through all four columns of this example, watching each carry land in the next column.
More digits just means more columns — the carrying rule never changes.
Five-Digit Addition
¹ ¹ ¹ ¹ 2 4 5 6 7 + 3 8 9 4 6 ----------- 6 3 5 1 3
Ones: 7+6=13 → 3 carry 1. Tens: 6+4+1=11 → 1 carry 1. Hundreds: 5+9+1=15 → 5 carry 1. Thousands: 4+8+1=13 → 3 carry 1. Ten-thousands: 2+3+1=6. Answer: 63,513
Adding Three or More Numbers
Column addition handles three or more addends just as easily. Add all values in each column and carry if the total is 10 or more.
Key Takeaways
- The column addition method works for any number of digits.
- Always align by place value and work right to left.
- When adding three or more numbers, a column can carry 2 or more.
- Estimate first (round to leading digits) to check your answer is reasonable.
Practice: Add Large Numbers
A fresh 4 or 5-digit addition appears every time. If you get it wrong (or leave it blank), we'll go through every column together.