This document provides an introduction to basic arithmetic concepts including the four fundamental operations of addition, subtraction, multiplication, and division. It explains key terminology like digits, whole numbers, fractions, and decimal numbers. Examples are provided for how to perform each operation by hand including adding and subtracting with carrying and borrowing, multi-digit multiplication, and long division. The document also covers converting between whole numbers and fractions, reducing fractions, and changing between improper and mixed numbers. Practice problems with answers are included throughout to help reinforce the concepts.