Asterisk — Definition, Formula & Examples
The asterisk (*) is the star-shaped symbol used in math most commonly to show multiplication, especially when typing on a keyboard or calculator where the traditional × sign is unavailable.
The asterisk is a typographic symbol (*) that serves multiple roles in mathematics: as a multiplication operator (e.g., ), as a superscript denoting a complex conjugate (), as the convolution operator (), and in computer science as the Kleene star indicating zero or more repetitions of a pattern.
How It Works
In everyday math, the asterisk works just like the × sign. When you see , you multiply 4 by 7 to get 28. You encounter this form constantly in spreadsheets, calculators, and programming languages. In more advanced mathematics, the asterisk takes on other meanings depending on context and placement. Written as a superscript like , it can denote a transpose, conjugate, or dual. Between two functions like , it can represent convolution.
Worked Example
Problem: Evaluate the expression typed into a spreadsheet.
Step 1: Treat each * as multiplication. First, evaluate the parentheses.
Step 2: Multiply from left to right.
Step 3: Complete the final multiplication.
Answer:
Why It Matters
Every programming language and spreadsheet application (Python, Excel, Google Sheets) uses * for multiplication, so recognizing this symbol is essential for coding and data work. In higher math courses like linear algebra and signal processing, the asterisk appears with entirely different meanings, so understanding that context determines its role prevents confusion.
Common Mistakes
Mistake: Assuming * always means multiplication in every math context.
Correction: In advanced topics, can mean convolution and can mean the complex conjugate. Always check the context to determine the intended operation.