Even and Odd

An even number is a number that is divisible by $2$ without a remainder.
To better understand this definition, think of an even number as a number that can be divided into pairs or into $2$ equal groups.
For example - If I have $4$ children, I can divide the number 4 into $2$ equal groups.
Group $1$ will have $2$ children and the second group will also have two children.

Let's practice -
Is the number $10$ an even number?
Let's ask ourselves - can we divide $10$ players into $2$ equal teams?
The answer is yes, if we divide the players into $2$ teams, each team will have 5 players.

So as we said, an even number is a number that is divisible by $2$ without a remainder.

Remainder is the leftover part that doesn't allow me to divide into $2$ equal groups.
For example - if there are $5$ players, I cannot divide them into $2$ groups without having a remainder.
In the first group there will be $2$, in the second group there will be $2$, and then I'm left with one player who cannot be divided, and this is called a remainder.

Luckily, there's a really cool trick that helps us determine if a number is even or odd.
We won't need to check each time if it can be divided into $2$ equal groups, instead we'll establish -
If the ones digit of the number is $​0$ or $2$ or $4$ or $6$ or $8$ - the number is even!
If not, the number is odd.

Reminder - The ones digit is the last digit of the number. When there is only one digit in a number, it is its ones digit.
Now let's practice!
Write 2 even numbers between $4$ and $10$:

Answer:
For a number to be even, its ones digit must be either $​0$ or $2$ or $4$ or $6$ or $8$
Therefore, we can write the numbers $6$ and $8$ as even numbers between $4$ and $10$.

Another exercise:
Is the number 24878 even?

Answer:
Yes!

Don't stress about the number being long. Just looking at the last digit $8$ is enough to determine that the number is indeed even.
Tip - How can we remember that specifically the digits $​0$,$2$,$4$,$6$,$8$ indicate an even number?
Notice that the definition of an even number is a number that is divisible by $2$ without a remainder and that its characteristic digits increase by steps of $2$.
And what about the number $​0$? $​0$ is an even number of course!

An odd number is the opposite of an even number. That means,
a number that is divisible by $2$ with a remainder.
To better understand this definition, think of an odd number as a number that cannot be divided into pairs or $2$ equal groups.
For example - if I have $7$ children, I cannot divide the number $7$ into $2$ equal groups.
Group $1$ will have $3$ children and the second group will have $4$ children.
If I divide into $2$ groups with $3$ children each, I will have one child left alone - which is called a remainder.

Let's practice-
Is the number $3$ an even number?
Let's ask ourselves - can we divide $3$ players into $2$ equal teams?
The answer is no, team $1$ will have $2$ players and the second team will have $1$ player.

At the beginning of the article, we learned that any number ending with a ones digit that is $​0$ or $2$ or $4$ or $6$ or $8$ is even, and therefore any number that ends with a different digit or is itself a different digit is an odd number!

And now let's practice!
Write $2$ odd numbers between $4$ and $10$:

Answer:
For a number to be odd, its ones digit must be different from $​0$ or $2$ or $4$ or $6$ or $8$
Therefore, we can write the numbers $5$ and $7$ as odd numbers between $4$ and $10$.

Another exercise:
Is the number $6479$ odd?

Answer:
Yes!
The ones digit of the number is $9$ and therefore it is odd.