10000

Ten thousand, written as 10,000 in decimal notation and spoken as “ten thousand,” is the natural number that follows 9,999 and precedes 10,001. It equals 10^4 and is a perfect square since 100 × 100 = 10,000. Its prime factorization is 2^4 × 5^4. In Roman numerals, it is commonly represented as X with a line over it (X̄), or in some contexts as a parenthesized X.

Name and language use: The English term derives from the combination of “ten” and “thousand.” The concept of a myriad, from the Greek myriás, has historically meant ten thousand and is used in some languages to signify a very large, indefinite quantity. In East Asia, the number is a basic counting unit: in Chinese it is wan (万) and in Japanese it is man (万). These terms appear in idioms and in large-number notation, where groups of four digits are common.

Mathematical significance: As a decimal base milestone, 10,000 is the first five-digit number and a central reference point in education and computation tied to the base-10 system. It serves as a convenient scale for rounding, estimation, and data presentation. It is also the square of 100, linking it to both decimal arithmetic and geometry.

Cultural usage: 10,000 appears in various cultural contexts as a symbol of abundance or a large quantity. In modern life, the shorthand 10k is widely used to indicate ten thousand items or steps, such as in finance, marketing, and health, where 10,000 steps a day is a commonly cited target.