Adding Two- and Three- Digit Numbers

Learn all about adding two-digit numbers and adding three-digit numbers in this free lesson, which includes practice problems.

Solving Stacked Addition Problems

To solve stacked addition problems, all you need are the skills you learned in Introduction to Addition.


As you saw, stacked addition problems are always solved from right to left. This means that you always start by adding the digits on the right.

Try This!

Solve the addition problems below. Then, check your answer by typing it into the box.

45 + 34 =
72 + 3 =
13 + 12 =

Adding Very Large Numbers

Stacked addition can also be used for adding larger numbers. No matter how many digits are in the numbers you're adding, you add them the same way: from right to left.

Try This!

Add these large numbers. Then, check your answer by typing it in the box.

214 + 262 =
101 + 505 =
787 + 11 =