Pronunciation of the number 1.
One ( 1) is a natural number after zero and before two.
It represents a single item.
A human typically has one head, nose, mouth, and navel (belly-button).
The Roman numeral for one is I.
mathematics, 1 is the multiplicative identity of common numbers. It is sometimes called the "unity".  It is also the only number for which these special facts are true.
n multiplied by 1 equals that number: n × 1 = n. For example, 7 × 1 = 7. Any number
n divided by 1 equals that number: n / 1 = n. For example, 7 / 1 = 7. Any number
n, other than 0, divided by itself always equals 1: n / n = 1. For example: 7 / 7 = 1. 1 cannot be divided with any other number so that the result is a natural number.
0.999... is a repeating decimal that is mathematically equal to 1. Many proofs have been made to show this is correct.
one is important for computer science, because the binary numeral system uses only 1s and 0s. In machine code and many programming languages, one means true and zero means false.
Germany and Austria, one is the grade for "very good". It is the best grade of six possible grades in Germany, and the best of five possible grades in Austria. In the Netherlands, one is the lowest grade, and ten the highest and the best. In Poland, one is also the lowest grade, but the highest is six. In numerology, the number one is a symbol for everything ( unity), the beginning, and God.
"List of Arithmetic and Common Math Symbols". Math Vault. 2020-03-17 . Retrieved . 2020-09-22
Weisstein, Eric W. "1". mathworld.wolfram.com . Retrieved . 2020-09-22