This book is about Basic Mathematics. It is mainly dedicated to mid, high-school and first-year university students, and their mathematics instructors. It can be considered as a reference book for practicing and going deep in the understanding of basic concepts of mathematics. Usually, instructors do not have the time to cover a large number of situations, this is why our manuscript provides a smooth, easy to read, and self-contained reference rich with exercises. It contains about 365 solved examples and exercises supplemented by 52 unsolved questions.