Home/Second Grade Math/Lesson 123
K-5 friendly lesson
One small step at a time.Read the idea, try the activity, and celebrate each win as you go.

Add 3-Digit Numbers Vertically (Carrying the 1s and 10s)

πŸ₯ž The Ultimate Stack! We are adding three huge columns down, and we might have to carry a One, AND carry a Ten!

Do this: Read the concept below, then try the quiz or activity.

Lesson 123 of 186

Concept

This is the exact same process you used for two-digit numbers, just with absolutely no limits on how high the answer can go.

🎯 The Double Carry Strategy:
Example: 385 + 472 = ?
  3 8 5
+ 4 7 2
---------
1. Ones: 5 + 2 = 7. (No carry needed).
2. Tens: 8 + 7 = 15! 
   * Write the 5 at the bottom of the Tens.
   * Carry the 1 to the top of the Hundreds column! Write it in a little circle.
3. Hundreds: Add the +1, the 3, and the 4. (1+3=4, 4+4=8). Write the 8!
4. Answer: 857!

Try it

Carry the cargo up the tower!

Instructions: Add down the columns. Start on the right. Carry if the number is 10 or more!

Problem 1:
   6 2 4
 + 1 9 3
---------
* Ones: 4 + 3 = ___
* Tens: 2 + 9 = 11. Write 1, carry the 1!
* Hundreds: 1 + 6 + 1 = ___
* Answer: ___
Problem 2:
  (+1)
   4 5 8
 + 3 2 4
---------
* Ones: 8 + 4 = 12. Write 2, carry the 1!
* Tens: 1 + 5 + 2 = ___
* Hundreds: ___
* Answer: ___
Problem 3:
   5 8 9
 + 2 1 1
---------
* Answer: ___
Problem 4 (Double Carry Warning!):
   3 6 5
 + 4 6 5
---------
* (Hint: 5+5=10. Carry! Then 1+6+6=13. Carry again!)
* Answer: ___
Complete & Continue β†’