Download Grade 9 Math Glossary

Math
Glossary
natural numbers
 The
numbers used for counting:
 {1, 2, 3, 4, ...}.
whole numbers
 The
set of whole numbers is:
 {0, 1, 2, 3, 4, 5, ...}.
numerator
 The
number above the fraction
bar that shows how many
equivalent parts are being
considered.
denominator
 The
number below the fraction
bar in a fraction.
 It shows the number of equal
parts in a whole.
factor
 Any
number that divides evenly
(without remainder) into the
given number:
 1, 2, 3 and 6 are factors of 6.
product
 The
answer to a multiplication
problem.
 6 is the product of 2 times 3.
factored
A
number is factored by writing it
as the product of two or more
numbers.
 6 is factored as 2 times 3.
prime number
A
natural number (except one)
that has only one and itself as
factors.
 2, 3, 5, 7, 11, 13, and 17 are
prime numbers.
composite number
A
composite number has at least
one factor other than itself and
one.
greatest common factor
(GCF)
 The
largest common factor of a
list of integers or the largest term
that is a factor of all terms in the
polynomial.
lowest terms
A
fraction is in lowest terms when
there are no common factors in
the numerator and denominator
(except 1).
reciprocals
 Pairs
of numbers whose product
is 1:
 1/3 and 3 are reciprocals.
quotient
 The
answer to a division problem.
sum
 The
answer to an addition
problem.
least common
denominator (LCD)
 Given
several denominators, the
smallest expression that is
divisible by all the denominators
is called the least common
denominator.
mixed number
A
whole number and a fraction
written together and understood
to be their sum.
difference
 The
answer to a subtraction
problem.
exponent (power)
A
number that indicates how
many times a factor is repeated:
 Given
23 the exponent is three.
base
 The
number that is a repeated
factor when written with an
exponent:
 Given 23 the base is two.
variable
A
variable is a symbol used to
represent an unknown number:
 In the term 3x the variable is x.
algebraic expression
 Any
collection of numbers or
variables joined by the basic
operations of addition,
subtraction, multiplication, or
division (except by zero), or the
operation of taking roots.
equation
A
statement that two algebraic
expressions are equal:
 Example: 4x = 5y.
number line
A
line with a scale that is used to
show how numbers relate to each
other.
negative number
A
number located to the left of
zero on a number line.
positive number
A
number located to the right of
zero on the number line.
signed numbers
 Numbers
that can be written with
a positive or negative sign.
integers
 The
set of integers is:
 {...-3, -2, -1, 0, 1, 2, 3,...}.
graph of a number
 The
point on a number line that
corresponds to a number is its
graph.
rational numbers
 Rational
numbers can be written
as the quotient of two integers,
with denominator not zero.
set-builder notation
 Set-builder
notation is used to
describe a set of numbers without
actually having to list all of the
elements.
irrational numbers
 Irrational
numbers cannot be
written as the quotient of two
integers but can be represented
by points on the number line.
real numbers
 All
numbers that can be
represented by points on the
number line, that is, all rational
and irrational numbers.
additive inverse
 Two
numbers that are the same
distance from zero on a number
line but on opposite sides of zero.
The sum of two additive inverses
equals zero.
term
A
number, a variable, or the
product or quotient of a number
and one or more variables raised
to powers.
numerical coefficient
 The
numerical factor in a term. In
the term 6x2 the numerical
coefficient is 6.
like terms
 The
same variables raised to
exactly the same powers. The
terms 2x2 and 7x2 are like terms.
unlike terms
 Terms
that do not have the same
variable or the variables are not
raised to the same powers. The
terms 2x2 and 7x3 are unlike
terms.
combining like terms
A
method of adding or subtracting
like terms by using the properties
of real numbers:
 2x2 + 7x2 = 9x2.