A quick reference to the math symbols you meet most often, grouped by topic. Each one shows the symbol, its name, and what it means. For statistics-specific notation, see the Statistics Symbols Reference, and for definitions of math terms, the Math Glossary.
Arithmetic and operations
| Symbol | Name | Meaning |
|---|---|---|
| + | Plus | Addition |
| − | Minus | Subtraction |
| × | Times | Multiplication |
| ÷ | Divide | Division |
| = | Equals | Is equal to |
| ≠ | Not equal | Is not equal to |
| ± | Plus-minus | Both the positive and negative value |
| % | Percent | Per hundred |
| √ | Square root | A value that squares to the number |
| ∛ | Cube root | A value that cubes to the number |
| x² | Exponent | x raised to a power |
| |x| | Absolute value | Distance from zero (always positive) |
Comparison and equality
| Symbol | Name | Meaning |
|---|---|---|
| < | Less than | Smaller than |
| > | Greater than | Larger than |
| ≤ | Less or equal | At most |
| ≥ | Greater or equal | At least |
| ≈ | Approximately | Roughly equal to |
| ≡ | Identical | Equivalent / defined as |
| ∝ | Proportional | Varies in direct ratio with |
| ∞ | Infinity | Unbounded, without end |
Algebra and calculus
| Symbol | Name | Meaning |
|---|---|---|
| ∑ | Sigma | Sum of a sequence of terms |
| ∏ | Pi (product) | Product of a sequence of terms |
| ! | Factorial | Product of all whole numbers up to n |
| f(x) | Function | Output of f for input x |
| ∫ | Integral | Area under a curve (calculus) |
| ∂ | Partial | Partial derivative (calculus) |
| ∆ | Delta | Change in a quantity |
| lim | Limit | Value a function approaches |
Geometry
| Symbol | Name | Meaning |
|---|---|---|
| ° | Degree | Unit of angle (360 in a circle) |
| ∠ | Angle | The angle formed by two rays |
| ⊥ | Perpendicular | Meets at a right angle |
| ∥ | Parallel | Lines that never meet |
| △ | Triangle | A three-sided polygon |
| π | Pi | Circle circumference / diameter, about 3.14159 |
| ≅ | Congruent | Same shape and size |
| ~ | Similar | Same shape, different size |
Set theory and logic
| Symbol | Name | Meaning |
|---|---|---|
| ∈ | Element of | Belongs to a set |
| ∉ | Not element of | Does not belong to a set |
| ⊂ | Subset | Contained within a set |
| ∪ | Union | All elements in either set |
| ∩ | Intersection | Elements in both sets |
| ∅ | Empty set | A set with no elements |
| ∧ | And | Logical conjunction |
| ∨ | Or | Logical disjunction |
| ⇒ | Implies | If first then second |
| ∀ | For all | Holds for every element |
| ∃ | There exists | At least one element |
| ∴ | Therefore | Conclusion follows |
Greek letters in math
Greek letters stand in for angles, constants, and statistical quantities throughout math and science.
| Symbol | Name | Meaning |
|---|---|---|
| α | Alpha | Angles, coefficients |
| β | Beta | Angles, coefficients |
| θ | Theta | An angle |
| π | Pi | The constant 3.14159… |
| Σ | Sigma (capital) | Summation |
| σ | Sigma | Standard deviation |
| μ | Mu | Mean (average) |
| λ | Lambda | Wavelength, eigenvalues |
| ρ | Rho | Density, correlation |
| Δ | Delta (capital) | Change or difference |
FAQ
What does the ∑ symbol mean? The capital Greek sigma means “sum” — add up every term in the sequence it describes.
What is the difference between = and ≡? A single equals sign states two things are equal; the triple bar means they are identical by definition or equivalent for all values.
Why are Greek letters used in math? They give mathematicians a large, distinct set of single-character names for angles, constants, and variables without reusing the Latin alphabet.