Why Computers Use Asterisk (*) for Multiplication

When writing code, programmers often employ the asterisk (*) symbol for multiplication. This preference is rooted in several practical and historical reasons that ensure clarity, consistency, and efficiency in programming languages. Let's delve into the rationale behind this convention.

Avoiding Ambiguity

One of the primary reasons for using asterisk (*) for multiplication is to avoid ambiguity. In algebraic expressions, the letter 'x' is commonly used as a variable, particularly in equations like (3x5 15). If multiplication were denoted by 'x', it could easily be confused with a variable name, leading to errors in the code.

Keyboard Availability

The asteriskkey is readily available on standard keyboards and is easy to type, especially in programming environments. In contrast, 'x' is a letter that is less frequently used as a symbol on a typewriter keyboard, making it an awkward choice for non-alphabetic operators in code.

Historical Context

Historically, early computer programming languages, such as Fortran, adopted the asterisk (*) as the standard multiplication operator. This convention was carried forward into subsequent languages like C, Java, and Python. The choice of asterisk persisted because it proved to be a practical and unambiguous symbol, which could be easily incorporated into programming syntax.

Readability and Clarity

The use of asterisk (*) can also enhance readability. In programming, it is crucial to clearly differentiate between operators and variables. For instance, consider the expression 45x9. Here, 'x' serves as a variable, not as an operator. In such contexts, the asterisk ensures that the multiplication operation is unambiguously identified, making the code easier to understand and maintain.

Early Programming Constraints

When modern programming began, the available input devices were limited. Early tools like card punches, IBM 026 keypunch machines, and paper tape Friden Flexowriters had very limited character sets. These devices did not have lowercase letters or many special characters. Programming languages continued these early conventions because they were practical and familiar to the early programmers.

In summary, while 'x' is commonly used as a variable in mathematical notation, the asterisk (*) symbol is more practical for programming and computing contexts. This choice helps to avoid ambiguity, stays within the limitations of early keyboard and programming constraints, and enhances the readability of code. As programming continues to evolve, the standard of using asterisk (*) for multiplication remains a cornerstone of programming syntax.