MATH REFERENCE
Math glossary
A quick-reference glossary of the math terms you meet most often, grouped by area. Each definition is kept short and plain, so you can look up a word and move on. The terms span arithmetic, algebra, geometry, and statistics.
Arithmetic and numbers
| Term | Meaning |
|---|---|
| Integer | A whole number, positive, negative, or zero, with no fractional part. |
| Prime number | A whole number greater than 1 divisible only by 1 and itself. |
| Factor | A number that divides another exactly, with no remainder. |
| Multiple | The result of multiplying a number by an integer. |
| Numerator | The top number of a fraction, the part being counted. |
| Denominator | The bottom number of a fraction, the number of equal parts in the whole. |
| Percentage | A number expressed as a part of one hundred. |
| Absolute value | The distance of a number from zero, always non-negative. |
Algebra
| Term | Meaning |
|---|---|
| Variable | A symbol, often x, standing for an unknown or changeable value. |
| Coefficient | The number multiplying a variable, such as the 3 in 3x. |
| Term | A single number or variable product in an expression, separated by plus or minus. |
| Expression | A combination of numbers, variables, and operations with no equals sign. |
| Equation | A statement that two expressions are equal, joined by an equals sign. |
| Exponent | A small raised number showing how many times to multiply a base by itself. |
| Polynomial | An expression using only addition, subtraction, and whole-number powers of variables. |
| Quadratic | An equation or expression whose highest power is two. |
Geometry
| Term | Meaning |
|---|---|
| Perimeter | The total distance around a two-dimensional shape. |
| Area | The amount of surface a flat shape covers, in square units. |
| Volume | The space a solid occupies, in cubic units. |
| Radius | The distance from the center of a circle to its edge. |
| Diameter | The distance across a circle through its center, twice the radius. |
| Hypotenuse | The longest side of a right triangle, opposite the right angle. |
| Vertex | A corner point where edges or sides meet. |
| Pi | The constant ratio of a circle circumference to its diameter, about 3.14159. |
Statistics
| Term | Meaning |
|---|---|
| Mean | The average: the sum of values divided by how many there are. |
| Median | The middle value of a sorted data set. |
| Mode | The value that appears most often in a data set. |
| Range | The difference between the largest and smallest values. |
| Variance | The average of the squared distances of values from the mean. |
| Standard deviation | The square root of the variance, a measure of spread. |
| Probability | A number from 0 to 1 giving how likely an event is. |
| Outlier | A value far from the rest of the data. |
Keep learning
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FAQ
What is the difference between an expression and an equation?
An expression is a combination of numbers and variables with no equals sign; an equation states that two expressions are equal.
What is the difference between a factor and a multiple?
A factor divides a number exactly; a multiple is the result of multiplying a number by an integer. So 3 is a factor of 12, and 12 is a multiple of 3.
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