2 (number) facts for kids

Quick facts for kids ← 1 2 3 →
−1 0 1 2 3 4 5 6 7 8 9 → ← 0 10 20 30 40 50 60 70 80 90 →
Cardinal	two
Ordinal	2nd (second / twoth)
Numeral system	binary
Factorization	prime
Gaussian integer factorization
Prime	1st
Divisors	1, 2
Greek numeral	Β´
Roman numeral	II
Roman numeral (unicode)	Ⅱ, ⅱ
Greek prefix	di-
Latin prefix	duo- bi-
Old English prefix	twi-
Binary	102
Ternary	23
Senary	26
Octal	28
Duodecimal	212
Hexadecimal	216
Greek numeral	β'
Arabic	٢
Urdu
Ge'ez	፪
Bengali	২
Chinese numeral	二，弍，贰，貳
Devanāgarī	२
Telugu	౨
Tamil	௨
Hebrew	ב (Bet)
Khmer	២
Korean	이，둘
Thai	๒

2, also known as Two, is a number and a numeral. It is the number that comes right after 1 and just before 3. In Roman numerals, you write it as II.

The Number 2 in Math

The number 2 is super important in math! For example, 1 + 1 = 2.

Even Numbers

A number is called even if you can divide it by 2 without anything left over. If a number ends in 0, 2, 4, 6, or 8, it's an even number. This also means that when you multiply any number by 2, the answer will always be an even number.

Prime Numbers

Two is special because it's the smallest and the only even prime number. A prime number is a whole number greater than 1 that has only two factors: 1 and itself. The next prime number after 2 is 3. Two and three are the only prime numbers that are right next to each other. All other even numbers bigger than 2 are not prime because you can always divide them by 2.

Binary System

The number 2 is the base for the binary system. This system is used in computers to store and process information. It's a very simple system that only uses two digits: 0 and 1.

Special Math Facts About 2

Two has some unique properties:

• 2 + 2 = 4
• 2 × 2 = 4
• 2² (2 to the power of 2) = 4

So, 2 + 2 = 2 × 2 = 2².

Also, powers of two (like 2, 4, 8, 16, 32, and so on) are very important in computer science.

Images for kids

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  This image shows how the symbol for the number 2 has changed over time.

See also

In Spanish: Dos para niños