Multiplication Dot — Definition, Formula & Examples
The multiplication dot (·) is a raised dot placed between two numbers or variables to indicate multiplication. It is commonly used in algebra and higher math as an alternative to the × symbol.
The interpunct or middle dot (·), when used as a multiplication operator, denotes the product of two quantities. Written as , it is equivalent to and is preferred in algebraic contexts where the × symbol might be confused with the variable .
How It Works
You place the dot at the midline between two quantities to show they are being multiplied. For example, means . In algebra, writing is clearer than because the × could look like the letter . Once variables are introduced, many textbooks drop even the dot and simply write , but the dot remains useful when multiplying two numbers side by side, such as , where no variable is present to signal multiplication.
Worked Example
Problem: Evaluate .
Step 1: Interpret each dot as multiplication.
Step 2: Add the two products together.
Answer:
Why It Matters
Once you start algebra, the × sign becomes risky because it looks like the variable . The multiplication dot lets you write expressions like without any ambiguity. Science courses and standardized tests use it frequently, so recognizing it early avoids confusion.
Common Mistakes
Mistake: Confusing the multiplication dot (·) with a decimal point (.)
Correction: The multiplication dot sits at the middle of the line (), while a decimal point sits at the bottom (). Pay attention to the vertical position of the dot to determine its meaning.