Arithmetic Do Basic is a term used to describe the three basic operations of mathematics: addition, subtraction, and multiplication. Addition is the process of combining two or more numbers to get a total, and is represented by the three-letter word 'ADD'. Subtraction is the process of taking away one number from another, and is represented by the four-letter word 'adds'. Finally, multiplication is the process of multiplying two or more numbers together, and is represented by the eight-letter word 'MULTIPLY'. These three operations are the foundation of all mathematical calculations and are essential for understanding more complex mathematical concepts.