Topics in a Pre-Algebra Course

To learn more about a topic listed below, click the topic name to go to the corresponding MathWorld classroom page.

Absolute Value	The distance of a number from the origin. Absolute value is an example of a norm.
Arithmetic	The branch of mathematics dealing with numerical computation. Arithmetical operations include addition, congruence calculation, division, factorization, multiplication, power computation, root extraction, and subtraction.
Arithmetic Series	A series in which the difference between any two consecutive terms is a constant.
Associative	An operation * is associative if x*(y*z) = (x*y)*z for all x, y, and z.
Base	The number of digits in a number system. The same word is used in the context of logarithms.
Cartesian Coordinates	The usual coordinate system, originally described by Descartes, in which points are specified as distances to a set of perpendicular axes. Also called rectangular coordinates.
Commutative	An operation * is commutative if x*y = y*x for all x and y.
Decimal Expansion	The usual "base 10" representation of a real number.
Distributive	Having the property, in multiplication, that x(y+z) = xy + xz.
Divisor	An integer that divides a given integer with no remainder. A synonym for factor.
Factorial	The product of the first n positive integers, denoted n!.
Fraction	A rational number expressed in the form a/b, where a is known as the numerator and b as the denominator.
Function Graph	The set of points showing the values taken by a function. This type of plot is called simply a "graph" in common parlance, but is distinct from a collection of points and lines that mathematicians refer to when they speak of a "graph."
Geometric Series	A series in which the ratio of any two consecutive terms is always the same.
Greatest Common Divisor	For two or more integers, the largest integer dividing all of them.
Integer	One of the numbers ..., -2, -1, 0, 1, 2, ....
Intersection	(1) For two sets A and B, the set of elements common to A and B. (2) For two or more geometric objects, the set of points that are common to both of them.
Interval	A connected piece of the real number line. An interval can be open or closed at either end.
Irrational Number	A number that cannot be written as a fraction. Irrational numbers have decimal expansions that neither terminate nor become periodic.
Least Common Multiple	For two or more integers, the smallest number that is a multiple of all of them.
Line	The infinite extension in both directions of a line segment, which is the path of shortest distance between two points.
Origin	The point with all-zero coordinates in Cartesian coordinates, or the central point in polar coordinates.
Polynomial	A mathematical expression involving a sum of powers in one or more variables multiplied by coefficients.
Power	An exponent to which a given quantity is raised.
Prime Factor	A divisor that is also a prime number.
Prime Factorization	The factorization of a number into its constituent primes. Also called prime decomposition.
Prime Number	A positive integer that has exactly one positive integer divisor other than 1 (i.e., no factors other than 1 and itself). Prime numbers are often simply called primes.
Pythagorean Theorem	An equation relating the lengths of the sides of a right triangle. Given two sides, the length of the third can be determined.
Quotient	The result of dividing one number by another.
Rational Number	A real number that can be written as a quotient of two integers.
Real Line	A line with a fixed scale so that every real number corresponds to a unique point on the line.
Real Number	The set of all rational and irrational numbers.
Relatively Prime	A term describing integers that share no common positive divisors except 1.
Right Angle	An angle that measures exactly 90 degrees.
Rounding	The approximation of a number by truncating and possibly adjusting the last digit of interest based on digits appearing after it.
Sequence	A (possibly infinite) ordered list of numbers.
Series	An often infinite sum of terms specified by some rule.
Set	A finite or infinite collection of objects in which order has no significance and multiplicity is generally also ignored.
Square Number	An integer that is the square (i.e., second power) of another integer.
Square Root	A square root of x is a number r such that r*r = x. MathWorld