Learn the basics of subtraction with this free lesson, which includes subtraction basics as well as interactives for you to practice.

### What is subtraction?

**Subtraction** is taking things away. When you have an amount and you **subtract** from it, the amount becomes smaller. Subtraction happens a lot in real life.

For instance, imagine we have 8 eggs...

For instance, imagine we have 8 eggs...and we use a few. We're subtracting from the eggs we started with.

We can count the number of eggs to find out how many are left.

We can count the number of eggs to find out how many are left.

We can count the number of eggs to find out how many are left.

We can count the number of eggs to find out how many are left.

We can count the number of eggs to find out how many are left.

We can count the number of eggs to find out how many are left.

Five eggs are left. If you start with eight eggs and use three of them, then five eggs are left.

As we saw, if you have 8 eggs and **subtract** 3 of them, you'll have 5 eggs left. In other words:

8 - 3 = 5

8 - 3 = 5 is a** mathematical equation**. You could read it like this: five minus three equals two. As we learned in Introduction to Addition, a mathematical equation is basically a **math sentence** that uses numbers and **symbols**. When we write a subtraction equation, we use two symbols: - and =.

The **minus sign** (-) means one thing is being subtracted from another. This is why we put it after the first group of eggs — we had 8 eggs and subtracted 5 of them.

#### Try This!

Fill in the blanks in the expressions below.

#### The Equals Sign

The other symbol in our equation is the **equals sign** (**=**). As we learned in Introduction to Addition, the equals sign means two numbers or expressions are **equivalent**, or **equal**. Even though they might look different, they **mean the same thing**.

In our eggs example, since 3 eggs were left, we wrote 3 to the right of the equals sign. That shows each side means 3. 3 eggs on the left, and the number 3 on the right. Both sides are equal.