Understanding Even and Odd Numbers

Learning to tell the difference between even and odd numbers is an important and fun math skill! It all comes down to sharing equally.

What is an Even Number?

An even number is a number that can be split into two equal groups with none left over.

For example, if you have $6$ cookies and share them between two friends, each friend gets exactly $3$ cookies. There are no cookies left over, so $6$ is an even number.

The Even Number Rule: All even numbers end in $0, 2, 4, 6,$ or $8$.

What is an Odd Number?

An odd number is a number that cannot be split into two equal groups. When you try to divide it into two groups, there is always one left over.

For example, if you have $7$ cookies and share them between two friends, each friend gets $3$ cookies, but there is $1$ cookie left over! Because of that leftover cookie, $7$ is an odd number.

The Odd Number Rule: All odd numbers end in $1, 3, 5, 7,$ or $9$.

The "Ones Digit" Trick

What if you have a big number, like $17$ or $24$? You don't need to draw cookies to figure it out! Just look at the ones digit (the very last number on the right).

• Let's look at $17$: The ones digit is $7$. Since $7$ is an odd number, $17$ is odd.
• Let's look at $24$: The ones digit is $4$. Since $4$ is an even number, $24$ is even.

Let's Practice!

Here are a few examples to test your skills:

1. Is $17$ even or odd? Look at the last digit, which is $7$. Since $7$ is odd, $17$ is odd.

2. Find the even numbers: $3, 8, 11, 14, 21$ Check the ones digit for each number. The numbers that end in $0, 2, 4, 6,$ or $8$ are $8$ and $14$.

3. Write the next 3 even numbers after $24$ When counting by evens, we skip over the odd numbers (skip counting by $2$). After $24$, the next even numbers are $26, 28,$ and $30$.