Multiplication's the mathematical operation of scaling one number by another. It's one of the four basic operations in elementary arithmetic (the others being addition, subtraction and division). Multiplication's defined for whole numbers in terms of repeated addition; for example, 3 multiplied by 4 (often said as "3 times 4") can be calculated by adding 3 copies of 4 together: » 4 + 4 + 4 = 12.!, Multiplication of rational numbers (fractions) and real numbers's defined by systematic generaliz… (More on Multiplication)