18 (number) facts for kids
Quick facts for kids
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|---|---|---|---|---|
| Cardinal | eighteen | |||
| Ordinal | 18th (eighteenth) |
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| Factorization | 2 × 32 | |||
| Greek numeral | ΙΗ´ | |||
| Roman numeral | XVIII | |||
| Binary | 100102 | |||
| Ternary | 2003 | |||
| Senary | 306 | |||
| Octal | 228 | |||
| Duodecimal | 1612 | |||
| Hexadecimal | 1216 | |||
Eighteen is a number. It comes right after seventeen and just before nineteen. It is an even number, which means you can divide it by two without any remainder.
You can divide 18 by several numbers: 1, 2, 3, 6, 9, and 18 itself. In many countries, 18 is a very important age. It's often when people are considered adults (this is called the age of majority). It's also usually the age when you can vote in elections.
What is the Number 18?
The number 18 is a natural number, meaning it's a counting number like 1, 2, 3, and so on. It's a positive number.
18 in Mathematics
In Roman numerals, the number 18 is written as XVIII. This uses the Roman symbols for ten (X) and eight (VIII).
The number 18 has many multiples. Multiples are numbers you get when you multiply 18 by another whole number. Some examples are 36 (18 x 2), 54 (18 x 3), 72 (18 x 4), 90 (18 x 5), and 108 (18 x 6).
When you break 18 down into its prime factorization, it means finding the prime numbers that multiply together to make 18. The prime factorization of 18 is 2 x 3 x 3. You can also write this in a shorter way using exponents as 2 x 32.
18 in Everyday Life
As mentioned, 18 is a special age in many places around the world.
- Age of Majority: This is the age when a person is legally considered an adult. This means they can sign contracts, live on their own, and are responsible for their own actions.
- Voting Age: In most countries, you must be 18 years old to vote in elections. This allows young adults to have a say in how their country is run.
- Driving Age: In many places, 18 is the age when you can get a full driver's license.
