Can someone please clearly explain what is going on here with Fibonacci and his numbers. (The Liber abbaci begins"These are the nine figures of the Indians: 9 8 7 6 5 4 3 2 1. With these nine figures, and with the sign 0 which in Arabic is called zephirum, any number can be written as will be demonstrated [5]." Next he explains the Arabic rules for working with the Indian Numerals [1, p. 606]. Fractions are placed to the left of integers, and the fraction bar is used. The basic rules for these are outlined below (the examples are based on examples in the Dictionary of Scientific Biography, p. 607 and Lneburg, pp. 68-81.))

What is the decimal system he introduced all about? Please provide a clear explanation!

2 2 25 25 3 2-5 6 767 67 67 25 25 25 67 6-7? 6-7 6-7 2 2 25 25 3 2-5 6 767 67 67 25 25 25 67 6-7? 6-7 6-7