## Abridged Glossary of Terms

absolute value
The positive value for a real number, disregarding the sign. Written |x|. For example, |3|=3, |-4|=4, and |0|=0.
addition
The process of adding two numbers to obtain their sum.
arithmetic
The type of mathematics that studies how to solve problems involving numbers (but no variables).
base
In the expression x^{y}, x is called the base and y is the exponent.
common denominator
A multiple shared by the denominators of two or more fractions.
denominator
In the fraction x/y, x is called the numerator and y is called the denominator.
distributive law
The formula a(x+y)=ax+ay.
dividend
In the expression "a divided by b", a is the dividend and b is the divisor.
division
A basic arithmetical operation determining how many times one quantity is contained within another.
divisor
In the expression "a divided by b", a is the dividend and b is the divisor.
divisor
The nonzero integer d is a divisor of the integer n if n/d is an integer.
equation
A statement that two expressions are equal to each other.
even number
An integer that is divisible by 2.
exponent
In the expression x^{y}, x is called the base and y is called the exponent.
factor (noun)
An exact divisor of a number. Example: 7 is a factor of 28, because 28 can be divided by 7.
factor (verb)
To find the factors of a number.
factorial
n! (read n factorial) is equal to the product of the integers from 1 to n.
fraction
An expression of the form a/b.
greatest common divisor
The greatest common divisor of a sequence of integers, is the largest integer that divides each of them exactly.
greatest common factor
Same as greatest common divisor.
hypotenuse
The longest side of a right triangle.

imaginary number
A complex number of the form xi where x is real and i=sqrt(-1).
imaginary part
The imaginary part of a complex number x+iy where x and y are real is y.
inequality
The statement that one quantity is less than (or greater than) another.
irrational number
A number that is not rational.
least common multiple
The least common multiple of a set of integers is the smallest integer that is an exact multiple of every number in the set.
lowest common denominator
The smallest number that is exactly divisible by each denominator of a set of fractions.
lowest terms
A fraction is said to be in lowest terms if its numerator and denominator have no common factor.
multiplication
The basic arithmetical operation of repeated addition.
numerator
In the fraction x/y, x is called the numerator and y is called the denominator.
odd number
An integer that is not divisible by 2.
percent
A way of expressing a number as a fraction of 100.
perfect cube
An integer is a perfect cube if it is of the form m^{3} where m is an integer.
perfect power
An integer is a perfect power if it is of the form m^{n} where m and n are integers and n>1.
perfect square
An integer is a perfect square if it is of the form m^{2} where m is an integer.
power
A number multiplied by itself a specified number of times.
prime
A prime number is an integer larger than 1 whose only positive divisors are 1 and itself.
product
The result of multiplying two numbers.
quotient
The result of a division.

rational number
A rational number is a number that is the ratio of two integers. All other real numbers are said to be irrational.
real part
The real number x is called the real part of the complex number x+iy where x and y are real and i=sqrt(-1).
remainder
The number left over when one number is divided by another.
repeating decimal
A decimal whose digits eventually repeat.
right angle
An angle formed by two perpendicular lines; a 90 degree angle.
right triangle
A triangle that contains a right angle.
subtraction
A basic operation of arithmetic in which you take away one number from another.
sum
The result of adding two or more numbers.