Natural number

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Natural numbers example
 (0) 1   2   3   4   5   6   7   8   9   10  
11 12 13 14 15 16 17 18 19   20  
21 22 23 24 25 26 27 28 29   30  
31 32 33 34 35 36 37 38 39   40  
41 42 43 44 45 46 47 48 49   50  
51 42 53 54 55 56 57 58 59   60  
61 62 63 64 65 66 67 68 68   70  
71 72 73 74 75 76 77 78 79   80  
81 82 83 84 85 86 87 88 89   90  
91 92 93 94 95 96 97 98 99  
100   200   300   400   500  
600   700   800   900  
1000   2000   3000   4000   5000  
6000   7000   8000   9000  
10,000   100,000   1,000,000  
1,000,000,000   1,000,000,000,000  

Numbers less than 0 (such as −1) are not natural numbers.

Natural numbers, also called counting numbers, are the numbers used for counting things. They are whole numbers (called integers), and never less than zero (i.e. positive numbers). The special number zero is sometimes considered a natural number. Examples of natural numbers can be seen in the box on the right. Whole numbers are the natural numbers, but whole numbers always include zero.

The next possible natural number can be found by adding 1 to the current natural number, producing a set of numbers that could continue "for ever".

Non-natural numbers[change | edit source]

The following types of number are not natural numbers:

How to write it[change | edit source]

\mathbf{N} or \mathbb{N} is the way to write the set of all natural numbers. Because some people say 0 is a natural number, and some people say it is not, people use the following symbols to talk about the natural numbers:

Symbol Meaning
\mathbb{N}^+ Positive numbers, without zero
\mathbb{N}^* Positive numbers without zero
\mathbb{N}_0 Positive numbers, with zero
\mathbb{N}_{>0} Positive numbers without zero
\mathbb{N} \setminus \{0\} Positive numbers without zero


Other pages[change | edit source]