How to Add Two Numbers up to Three Digits

Instructor: Melanie Needling
This lesson teaches you how to add up to three-digit numbers without regrouping. As a basic skill, adding will help you in various ways during each and every day.

What is Adding?

When we add, we put numbers together to find out how much their total is. You may think that the only time you have to add is in math class, but there are times outside of class you will need to add also. Being able to add is necessary to get through everyday life.

At School

How Many Chairs?

One day, John walked into his reading class. His teacher explained that they were going to watch Charlotte's Web in the gym with Mrs. Johnson's class. John's teacher asked John to go get enough chairs for both classes from the cafeteria. When John asked how many they needed, his teacher replied that one class has 27 students and the other class has 30 students. John had to figure out how many in all.

In this math problem, John had to add 27 and 30. The two numbers that you add together are called addends.

First, line up the two addends one on top of the other. The numbers in the ones column should be lined up and the numbers in the tens column should be lined up, like this:

Step 1

Next, add the ones column, like this:

Step 2

Now, add the tens column.

Step 3

After adding the number of chairs from each class together, John knew that he needed 57 chairs in all. When you combine the addends, you get the sum. The sum of the chairs is 57.

At Home

How Many Pennies?

One day, Lucy and Lynn were spending the day with their grandmother, whom they called GaGa. GaGa had a very large jar of pennies. She told Lucy and Lynn they could have the money, if they counted all of the pennies for her. The two girls each took some of the pennies to count. When Lucy counted hers, she had 345 pennies. Lynn counted 221 pennies. In order to know how many pennies were in the jar in all, the girls had to add.

In this math problem, the girls had to add 345 and 221. If you remember, these two numbers are called addends.

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