Multiplication

Multiplication is an elementary binary operation, written \(ab\), \(a \times b\), or \(a \cdot b\) (pronounced "\(a\) times \(b\)"). It is defined as repeated addition: \(a \times b = \underbrace{a + a + \cdots + a + a}_b\). The result of a multiplication problem is called the product.

For example, the product \(3 × 4\) is equal to the sum of four 3s: \(3 + 3 + 3 + 3\).

Like addition, multiplication is and : \(a \times b = b \times a\) and \((a \times b) \times c = a \times (b \times c)\). Repeated multiplication is called exponentiation.

In the fast-growing hierarchy, multiplication grows faster than \(f_1(n)\).

It is the second hyper operator.