What is this * symbol called in math?

In mathematics, the * symbol is most commonly called an asterisk.

While primarily known as the asterisk, its function depends on the context within the mathematical expression or equation. Here's a breakdown of its common uses:

• Multiplication: This is arguably the most frequent use, especially in programming languages and calculators. For example, 7 * 6 represents 7 multiplied by 6.
• Convolution: In signal processing and linear algebra, the asterisk represents convolution between two functions or sequences.
• Complex Conjugate: In complex number theory, z* sometimes denotes the complex conjugate of the complex number z.
• Statistical Significance: In statistical tables, asterisks are often used to denote the statistical significance of a result, where more asterisks typically mean higher significance (e.g., p<0.05, p<0.01, p<0.001).
• Placeholder or Wildcard: Less frequently, it can act as a placeholder or wildcard in certain abstract algebraic notations.

The specific meaning of the asterisk should be clear from the context in which it is used.