Arabic numerals
The first mentions of the numerals in the West are found in the "Codex Vigilanus" of 976.
Fibonacci
In the "Liber Abaci" (1202), Fibonacci introduced the so-called "modus Indorum" (method of the Indians), today known as the Hindu–Arabic numeral system. The book advocated numeration with the digits 0–9 and place value. The book showed the practical use and value of the new Hindu-Arabic numeral system by applying the numerals to commercial bookkeeping, converting weights and measures, calculation of interest, money-changing, and other applications. The book was well-received throughout educated Europe and had a profound impact on European thought. No copies of the 1202 edition are known to exist.