Leonardo Pisano (Fibonacci)

If anyone has been able to solve all the problems I have proposed, let him come to me, and I will give him a prize.

I have been impelled by a certain desire for knowledge to learn the art of computation from the Egyptians, Syrians, Greeks, and Indians.

The nine Indian figures are 9 8 7 6 5 4 3 2 1. With these nine figures, and with the sign 0 which the Arabs call zephirum, any number can be written.

When I had been introduced to the art of computation, the knowledge of all its branches, and the various methods of calculation, I found that it was very different from what I had learned in my own country.

I have striven to compose this book to the best of my ability, and to make it clear and easy to understand for all who wish to learn.

The method of the Indians surpasses any known method of calculation. It is a wonderful method. They do their computations using nine figures and the sign zero.

I have shown how to solve many problems, both in arithmetic and geometry, and I have also given many examples of how to apply these methods to practical affairs.

I have also included a chapter on the extraction of roots, which is a very important part of arithmetic.

I have also included a chapter on the rule of three, which is a very useful rule for solving many problems.

I have also included a chapter on the calculation of interest, which is a very important part of commercial arithmetic.

I have also included a chapter on the calculation of profit and loss, which is a very important part of commercial arithmetic.

I have also included a chapter on the calculation of partnerships, which is a very important part of commercial arithmetic.

I have also included a chapter on the calculation of exchange rates, which is a very important part of commercial arithmetic.

I have also included a chapter on the calculation of weights and measures, which is a very important part of commercial arithmetic.

I have also included a chapter on the calculation of alloys, which is a very important part of commercial arithmetic.

I have also included a chapter on the calculation of inheritances, which is a very important part of commercial arithmetic.

I have also included a chapter on the calculation of legacies, which is a very important part of commercial arithmetic.

I have also included a chapter on the calculation of wills, which is a very important part of commercial arithmetic.

I have also included a chapter on the calculation of dowries, which is a very important part of commercial arithmetic.

I have also included a chapter on the calculation of taxes, which is a very important part of commercial arithmetic.