Equimultiplicity and blowing up Book

This book by Michael Closs is a classic in the area of cultural mathematics (which also goes by the name Ethnomathematics). The idea of the book is to present mathematics of indigenous groups of the Americas. There are many wonderful connections between culture and mathematics, and reading 'Native American Mathematics' allows us to see differences between how mathematics is perceived in Western culture and how it is perceived in non-Western cultures, specifically of the Americas. For example, in the first chapter on counting and number systems, there are many examples of creative ways interpreting numbers, by people of different cultures. Descriptions include how some cultures count using subtraction or multiplication, such as to describe the number nine in terms of 'ten minus one', or the number twelve as 'four times three'. In other chapters, one can learn about different kinds of calendars, such as those of the Nootka, the Aztecs, and the Maya, as well as cultural interpretations of numbers by cultures such as the Ojibwe and Inuit cultures. There is also a very good description of Inca mathematics by Marcia Ascher. There is a lot interesting information in this book, and it is not just formulas and equations - most of the book can be easily understood by reading it leisurely.