1. The problem is to understand the meaning of "Liber abaci" and its significance. 2. "Liber abaci" is Latin for "Book of Abacus" or "Book of Calculation". 3. It is a famous book written by Fibonacci, an Italian mathematician. 4. The book introduced the Hindu-Arabic numeral system to Europe, which is the basis of the numbers we use today. 5. This numeral system includes digits 0 through 9 and the concept of place value, which made calculations easier compared to Roman numerals. 6. The book played a crucial role in the development of modern arithmetic and algebra. Final answer: "Liber abaci" means "Book of Abacus" and is a famous book by Fibonacci that introduced the Hindu-Arabic numeral system to Europe.