A Friendly Introduction to Differential Equations
Differential equations
Mathematics
n this book, there are five chapters: The Laplace Transform, Systems of Homogeneous Linear Differential Equations (HLDE), Methods of First and Higher Orders Differential Equations, Extended Methods of First and Higher Orders Differential Equations, and Applications of Differential Equations. In addition, there are exercises at the end of each chapter above to let students practice additional sets of problems other than examples, and they can also check their solutions to some of these exercises by looking at "Answers to OddNumbered Exercises" section at the end of this book. This book is a very useful for college students who studied Calculus II, and other students who want to review some concepts of differential equations before studying courses such as partial differential equations, applied mathematics, and electric circuits II. This book is available online for free in google books and ResearchGate in PDF format under a Creative Commons license.
Mohammed Kaabar
Arithmetic for College Students
Arithmetic
Mathematics
This book is a course on arithmetic designed for college students. It covers whole numbers, fractions, decimals, percents, ratios and proportions, measurement, and integers. Geometry and statistics are integrated throughout the text rather than covered in independent sections. The textbook does not include exercises. Instead, a collection of handouts/worksheets is available, as well as online homework.
License: Creative Commons Attribution. This license is considered to be some to be the most open license since it is the least restrictive. It allows reuse, remixing, and distribution (including commercial), only requiring attribution. The content can be remixed into content of other license, but on the other hand it allows the remix to be put under a more restrictive license.
MITE
David Lippman
http://www.opentextbookstore.com/details.php?id=13
Scottsdale Community College
Cut Rita Zahara
Creative Commons
Textbooks
Basic Arithmetic Student Workbook
Basic Arithmetic
Arithmetic
Mathematics
This workbook was created through the efforts of three instructors at Scottsdale Community College in Scottsdale, Arizona, has been used by thousands of students, and is continually improved. This workbook contains have lessons that were carefully and thoughtfully crafted to lead students on a path to understanding numbers and arithmetic.
License: Creative Commons Attribution Sharealike. This license is considered to be some to be the most open license. It allows reuse, remixing, and distribution (including commercial), but requires any remixes use the same license as the original. This limits where the content can be remixed into, but on the other hand ensures that noone can remix the content then put the remix under a more restrictive license.
Donna Gaudet
Amy Volpe
Jenifer Bohart
http://www.opentextbookstore.com/details.php?id=24
Cut Rita Zahara
Creative Commons
Textbook
Introduction to Arithmetic Groups
Arithmetic

Dave Witte Morris
https://arxiv.org/src/math/0106063v6/anc/IntroArithGrpsFINAL.pdf
Deductive Press
2015
Baihaqi
Creative Commons
PDF
English
Textbooks