In this lesson, you will learn how you can make sure that an addition equation is balanced.

You will discover how this is the same as making sure both sides are equal. Then, learn how you can find the missing number.

## What are Addition Equations?

As you work your way through your math lessons, you will come across many **addition equations**. These are math equations that involve the addition operator.

You will have some things being added on the left side being equal to some things being added on the right side. Because the left and right sides are equal, both sides will be equal to the same number.

## A Balanced Addition Equation

For example, you might have an equation like 4 + 1 = 2 + 3. This is an addition equation that has already been solved because both sides equal the same thing.

4 + 1 is equal to 5, and so is 2 + 3. This is called a **balanced addition equation**. You can think of these addition equation problems as making sure that both you and your friend are getting the same amount. For example, both you and your friend, in this case, have 5 cheeseburgers each.

## Balancing An Addition Equation

When you come across these problems, oftentimes one value will be missing. It is your job to find this value.

Solving such problems involves balancing your addition equation. For example, you might see 11 + 3 = 8 + ?, where you need to find which value needs to be added to the 8 to make the equation work.The key to solving these problems is to make sure that both sides are equal to each other, or are balanced. It is often helpful to think in terms of something you know very well or can picture in your head. I like cheeseburgers, so I often will use cheeseburgers as a mental image.

If I am the left side and the right side is my friend, for this equation I will picture 11 cheeseburgers plus 3 cheeseburgers for me. That equals 14 cheeseburgers for me.In order to balance this addition equation, my friend will need the same number of cheeseburgers. My friend currently has 8 cheeseburgers, so how many more cheeseburgers does she need so that she has a total of 14 cheeseburgers? To find this out, I can subtract 8 from 14.

I get 14 – 8 = 6. My friend needs 6 cheeseburgers to make this addition equation true. The answer then is 6.The first step to balancing an addition equation is to add the side with no missing number. This sum is what the side with the missing number needs to equal. To find the missing number, you take the number shown on the side with the missing value and subtract it from the sum that you found for the other side.

This is your answer.

## Example

Let’s take a look at another example.Balance this equation:**40 + ? = 10 + 50**To solve this problem, first locate the side with no missing values. This is the right side. Adding this side, you get 10 + 50 = 60. To balance this addition equation, you need to make sure that the side with the missing value is equal to the same 60. What number added to 40 will make 60? To find this answer, you take your 40 and subtract it from the 60.

You get 60 – 40 = 20. So, 20 is your answer.

## Lesson Summary

Let’s review what you’ve learned. **Addition equations** are math equations that involve the addition operator.

A **balanced addition equation** is one where both sides are equal to the same number. To balance an addition equation, you first add the side with no missing values. This is the sum that the other side must equal. You then take the number that is present on the side with the missing value, and you subtract it from your sum.

This is your answer.

## Learning Outcomes

When you are done with this lesson, you should be capable to:

- Explain addition equations
- Describe how to create a balanced addition equation
- Solve examples of balanced equations