How Many Books in Euclid Elements?

There are a total of 13 Euclid books. The first four books are books dealing with geometry. The next series of books, five through ten, deal with ratios and proportions, still heavily dealing with how they relate to geometry. The final three books deal with the spatial geometry. Spacial being relation to space and dimension. These books are widely considered to be the masterpieces that set many standards for math.