Numbers and symbols
Improper Fraction
A fraction which has a larger numerator than denominator. For example, 12/7 is an improper fraction.
Number Line
A line representing the set of all real numbers. The number line is typically marked showing integer values
Mixed Number
A number written as the sum of an integer and a proper fraction. For example, 5¾ is a mixed number. 5¾ is the sum 5 + ¾.
Composite Number
A positive integer that has factors other than just 1 and the number itself. For example, 4, 6, 8, 9, 10, 12, etc. are all composite numbers. The number 1 is not composite.
Fraction
A ratio of numbers or variables. Fractions may not have denominator 0.
Negative Number
A real number less than zero. Zero itself is neither negative nor positive.
Rational Numbers
All positive and negative fractions, including integers and so-called improper fractions. Formally, rational numbers are the set of all real numbers that can be written as a ratio of integers with nonzero denominator. Rational numbers are indicated by the symbol Q.
Integers
All positive and negative whole numbers (including zero). That is, the set {... , -3, -2, -1, 0, 1, 2, 3, ...}. Integers are indicated by either Z or J.
Even Number
An integer that is a multiple of 2. The even numbers are { . . . , -4, -2, 0, 2, 4, 6, . . . }.
Odd Number
An integer that is not a multiple of 2. The odd numbers are { . . . , -3, -1, 1, 3, 5, . . . }.
Factor of an Integer
Any integer which divides evenly into a given integer. For example, 8 is a factor of 24.
Digit
Any of the symbols 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9 used to write numbers. For example, the digits in the number 361 are 3, 6, and 1.
Inequality
Any of the symbols <, >, ≤, or ≥.
Constant
As a noun, a term or expression with no variables. Also, a term or expression for which any variables cancel out. For example, -42 is a constant. So is 3x + 5 - 3x, which simplifies to just 5. As an adjective, constant means the same as fixed. That is, not changing or moving.
Irrational Numbers
Real numbers that are not rational. Irrational numbers include numbers such as π, e, etc.
Denominator
The bottom part of a fraction. For 3/5 , the denominator is 5.
Greatest Common Factor
The largest integer that divides evenly into each of a given set of numbers. Often abbreviated GCF or gcf. For example, 6 is the gcf of 30 and 18. Sometimes GCF is written using parentheses: (30, 18) = 6.
Median of a Set of Numbers
The median of a set of numbers is the value for which half the numbers are larger and half are smaller. If there are two middle numbers, the median is the arithmetic mean of the two middle numbers.
Arithmetic Mean
The most commonly used type of average. To find the arithmetic mean of a set of n numbers, add the numbers in the set and divide the sum by n.
Whole Numbers
The numbers 0, 1, 2, 3, 4, 5, etc.
Cardinal Numbers
The numbers 1, 2, 3, . . . as well as some types of infinity. Cardinal numbers are used to describe the number of elements in either finite or infinite sets.
Multiplicative Inverse of a Number
The reciprocal of x is . In other words, a reciprocal is a fraction flipped upside down. Multiplicative inverse means the same thing as reciprocal.
Difference
The result of subtracting two numbers or expressions. For example, the difference between 7 and 12 is 12 - 7, which equals 5.
Least Common Multiple
The smallest positive integer into which two or more integers divide evenly. For example, 24 is the LCM of 8 and 12. Sometimes the LCM is written using brackets: [8, 12] = 24.
Least Common Denominator
The smallest whole number that can be used as a denominator for two or more fractions. The least common denominator is the least common multiple of the original denominators.
Set Braces
The symbols { and } which are used to indicate sets.
Numerator
The top part of a fraction 12/47. For , the numerator is 12
Exponentiation
The use of exponents.
Average
This almost always refers to the arithmetic mean. In general, however, the average could be any single number that represents the center of a set of values.
Prime Factorization
Writing an integer as a product of powers of prime numbers 30 = 2*3*5
Exponent
x in the expression a^x. For example, 3 is the exponent in 2^3.