3 (number)

The number three (3) is one more than two and one less than four. It is the first Mersenne prime. Three is an important number for many cultures (groups...

as −3 and +3. A number and its opposite always add to zero. So the sum of −3 and +3 is 0. We can write this either as −3 + 3 = 0 or as 3 + (− 3) = 0...

1 3 + 3 3 + 5 3 + 7 3 + 9 3 + 11 3 + 13 3 + 15 3 . {\displaystyle 8128=2^{6}(2^{7}-1)=1+2+3+\cdots +125+126+127=1^{3}+3^{3}+5^{3}+7^{3}+9^{3}+11^{3}+13^{3}+15^{3}...

number nine (9) takes the shape of an upside-down six (6), is a multiple of 3, and the third square number after 4. Nine is also a composite number,...

abundant number is a number n{\displaystyle n} for which its sum of divisors is greater than 2n{\displaystyle 2n}. 12 is an abundant number because 1+2+3...

examples of odd numbers are 1, 3, 5, 7, 9, and 11. An integer that is not an odd number is an even number. If an even number is divided by two, the result...

a unique number that can identify a book. Cardinal numbers are used to measure how many items are in a set. For example, {A,B,C} has size "3". Ordinal...

The mass number (symbol: A) of an atom is the sum of the number of protons and the number of neutrons in the nucleus.: 20  The mass number is different...

example, 10 is a "triangular number" because 10=1+2+3+4{\displaystyle 10=1+2+3+4}. The first 25 triangular numbers are: 0, 1, 3, 6, 10, 15, 21, 28, 36, 45...

telephone network (PSTN) uses a phone numbers with a 3-digit area code and a 7-digit telephone number. This short article can be made longer. You can help...

circle. The number pi is approximately 3.14159265358979323… . Other examples of irrational number include the numbers e{\displaystyle e} and 3{\displaystyle...

Twenty-three is a natural number. It comes between twenty-two and twenty-four, and is an odd number. It is also the 9th prime number, after 2, 3, 5, 7, 11, 13, 17...

A number line is a line with integers (simply ordinary numbers, ...-3, -2, -1, 0, 1, 2, 3...) on it extending forever in both directions. Usually, zero...

2 (Two; /ˈtuː/ (listen)) is a number, numeral, and glyph. It is the number after 1 (one) and the number before 3 (three). In Roman numerals, it is II....

the second number is 1, and each number after that is equal to adding the two numbers right before it together. For example 0+1=1 and 3+5=8. This sequence...

used to be called the Official Municipality Characteristic Number or Municipality Code Number, is a group of numbers used to tell the difference between...

Georg Cantor. ℵ 0 {\displaystyle \aleph _{0}} is the number of numbers that are in the group 0, 1, 2, 3, ... (which goes on forever). Both the set of natural...

seven. The number seven is a natural number that comes after six and before eight. In Roman numerals, it is VII. In mathematics, the number seven is an...

(1, 2 and 3) are equal to the number itself (6). The next perfect number is 28. In Roman numerals, it is VI. The number six is an even number. This short...

number 9 can be found by multiplying 3 by 3. Another example is the number 12, which is obtained by multiplying 3, 2 and 2. All natural numbers (greater...