absolute value
The distance of a number
from zero; the positive value of a number.
acute angle
A positive angle measuring
less than 90 degrees.
acute triangle
A triangle each of whose
angles measures less than 90 degrees.
additive identity
The number zero is called
the additive identity because the sum of zero and any number is that number.
additive inverse
The additive inverse of
any number x is the number that gives zero when added to x. The
additive inverse of 5 is -5.
adjacent angles
Two angles that share both
a side and a vertex.
angle
The union of two rays with
a common endpoint, called the vertex.
arc
A portion of the
circumference of a circle.
area
The number of square units
that covers a shape or figure.
associative property
of addition
(a + b) + c = a + (b + c)
associative property
of multiplication
(a x b) x c = a x (b x c)
average
A number that represents
the characteristics of a data set.
axis of symmetry
A line that passes through a figure in such a
way that the part of the figure on one side of the line is a mirror reflection
of the part on the other side of the line.
base
The bottom of a plane
figure or three-dimensional figure.
Bisect
To divide into two
congruent parts.
Box and whisker plot
A type of data plot that
displays the quartiles and range of a data set.
Cartesian coordinates
A system in which points
on a plane are identified by an ordered pair of numbers, representing the
distances to two or three perpendicular axes.
central angle
An angle that has its
vertex at the center of a circle.
chord
A line segment that
connects two points on a curve.
circle
The set of points in a
plane that are a fixed distance from a given point, called the center.
circumference
The distance around a
circle.
coefficient
A constant that multiplies
a variable.
collinear
Points are collinear if
they lie on the same line.
combination
A selection in which order
is not important.
common factor
A factor of two or more
numbers.
common multiple
A multiple of two or more
numbers.
commutative property
of addition
a + b = b + a.
commutative property
of multiplication
a*b = b*a.
complementary angles
Two angles whose sum is 90 degrees.
composite number
A natural number that is
not prime.
cone
A three-dimensional figure
with one vertex and a circular base.
congruent
Figures or angles that
have the same size and shape.
constant
A value that does not
change.
coordinate plane
The plane determined by a
horizontal number line, called the x-axis, and a vertical number line, called
the y-axis, intersecting at a point called the origin. Each point in the
coordinate plane can be specified by an ordered pair of numbers.
coplanar
Points that lie within the
same plane.
counting numbers
The natural numbers, or
the numbers used to count.
counting principle
If a first event has n
outcomes and a second event has m outcomes, then the first event followed
by the second event has n times m outcomes.
cross product
A product found by
multiplying the numerator of one fraction by the denominator of another fraction
and the denominator of the first fraction by the numerator of the second.
cube
A solid figure with six
square faces.
cylinder
A three-dimensional figure
having two parallel bases that are congruent circles.
data
Information that is
gathered.
decimal number
The numbers in the base 10
number system, having one or more places to the right of a decimal point.
degree
A unit of measure of an
angle.
denominator
The bottom part of a
fraction.
dependent events
Two events in which the
outcome of the second is influenced by the outcome of the first.
diagonal
The line segment
connecting two nonadjacent vertices in a polygon.
diameter
The line segment joining
two points on a circle and passing through the center of the circle.
difference
The result of subtracting
two numbers.
digit
The ten symbols, 0, 1, 2, 3, 4, 5, 6, 7, 8,
and 9. The number 215 has three digits: 2, 1, and 5.
distributive property
a(b + c) = ab + ac
dividend
In a / b = c, a
is the dividend.
divisor
In a / b = c, b
is the divisor.
ellipse
The set of all points in a
plane such that the sum of the distances to two fixed points is a constant.
equation
A mathematical statement
that says that two expressions have the same value; any number sentence with an
=.
equilateral triangle
A triangle that has three
equal sides
equivalent equations
Two equations whose
solutions are the same.
equivalent fractions
Fractions that reduce to
the same number.
error of measurement
The difference between an
approximate measurement and the actual measure taken.
evaluate
To substitute number
values into an expression.
event
In
probability, a set of outcomes.
even number
A natural number that is
divisible by 2.
exponent
A number that indicates
the operation of repeated multiplication.
face
A flat surface of a
three-dimensional figure.
factor
One of two or more
expressions that are multiplied together to get a product.
factoring
To break a number into its factors.
formula
A equation that states a
rule or a fact.
fraction
A number used to name a
part of a group or a whole. The number below the bar is the denominator, and the
number above the bar is the numerator.
frequency
The number of times a
particular item appears in a data set.
frequency table
A data listing which also
lists the frequencies of the data.
graph
A type of drawing used to
represent data.
greatest common
factor (GCF)
The largest number that
divides two or more numbers evenly.
horizontal
A line with zero slope.
hypotenuse
The side opposite the
right angle in a right triangle.
identity property of
addition
The sum of any number and
0 is that number.
identity property of
multiplication
The product of 1 and any
number is that number.
improper fraction
A fraction with a
numerator that is greater than the denominator.
independent events
Two events in which the
outcome of the second is not affected by the outcome of the first.
inequality
A mathematical expression
which shows that two quantities are not equal.
infinity
A limitless quantity.
Infinity is not a numbwer.
inscribed angle
An angle placed inside a
circle with its vertex on the circle and whose sides contain chords of the
circle.
inscribed polygon
A polygon placed inside a
circle so that each vertex of the polygon touches the circle.
integers
The set of numbers
containing zero, the natural numbers, and all the negatives of the natural
numbers.
intercept
The x-intercept of a line
or curve is the point where it crosses the x-axis, and the y- intercept of a
line or curve is the point where it crosses the y-axis.
intercepted arc
The arc of a circle within
an inscribed angle.
interpolation
A method for estimating
values that lie between two known values.
intersecting lines
Lines that have one and
only one point in common.
inverse
Opposite. -5 is the
additive inverse of 5, because their sum is zero. 1/3 is the multiplicative
inverse of 3, because their product is 1.
inverse operations
Two operations that have
the opposite effect, such as addition and subtraction.
irrational number
A number that cannot be
expressed as the ratio of two integers.
isosceles triangle
A triangle with at least
two equal sides.
least common
denominator
The smallest multiple of
the denominators of two or more fractions.
least common multiple
The smallest nonzero number that is a multiple
of two or more numbers.
like fractions
Fractions that have the
same denominator.
line
A straight set of points
that extends into infinity in both directions.
line of symmetry
Line that divides a
geometric figure into two congruent portions.
line segment
Two points on a line, and
all the points between those two points.
locus
A path of points
logic
The study of sound
reasoning.
lowest terms
Simplest form; when the
GCF of the numerator and the denominator of a fraction is 1.
mean
In a data set, the sum of
all the data points, divided by the number of data points; average.
median
The middle number in a
data set when the data are put in order; a type of average.
midpoint
A point on a line segment
that divides the segment into two congruent segments.
mixed number
A number written as a
whole number and a fraction.
mode
A type of average; the
number (or numbers) that occurs most frequently in a set of data.
multiple
A multiple of a number is
the product of that number and any other whole number. Zero is a multiple of
every number.
multiplicative
identity
The number 1 is the
multiplicative identity because multiplying 1 times any number gives that
number.
multiplicative
inverse
The reciprocal of a
number.
mutually exclusive
events
Two or more events that
cannot occur at the same time.
natural numbers
The counting numbers.
negative number
A real number that is less
than zero.
normal
Perpendicular.
number line
A line on which every
point represents a real number.
numerator
The top part of a
fraction.
obtuse angle
An angle whose measure is
greater than 90 degrees.
obtuse triangle
A triangle with an obtuse
angle.
octagon
A polygon with 8 sides.
odd number
A whole number that is not
divisible by 2.
operation
Addition, subtraction,
multiplication, and division are the basic arithmetic operations.
opposites
Two numbers that lie the
same distance from 0 on the number line but in opposite directions.
ordered pair
Set of two numbers in
which the order has an agreed-upon meaning, such as the Cartesian coordinates
(x, y), where the first coordinate represents the horizontal position, and the
second coordinate represents the vertical position.
origin
The point (0, 0) on a
coordinate plane, where the x-axis and the y-axis intersect.
outcome
In probability, a possible
result of an experiment.
parallel
Two lines are parallel if
they are in the same plane and never intersect.
parallelogram
A quadrilateral with
opposite sides parallel.
pentagon
A five-sided polygon.
percent
A fraction, or ratio, in
which the denominator is assumed to be 100. The symbol % is used for percent.
perimeter
The sum of the lengths of
the sides of a polygon.
permutation
A way to arrange things in
which order is important
perpendicular
Two lines are
perpendicular if the angle between them is 90 degrees.
pi
The ratio of the
circumference of a circle to its diameter.
plane
A flat surface that
stretches into infinity.
point
A location in a plane or
in space, having no dimensions.
polygon
A closed plane figure made
up of several line segments that are joined together.
polyhedron
A three-dimensional solid
that is bounded by plane polygons.
positive number
A real number greater than
zero.
power
A number that indicates
the operation of repeated multiplication.
prime number
A number whose only
factors are itself and 1.
probability
For an experiment, the
total number of successful events divided by the total number of possible
events.
product
The result of two numbers
being multiplied together.
proper fraction
A fraction whose numerator
is less than its denominator.
proportion
An equation of fractions
in the form:
a/b = c/d
protractor
A device for measuring
angles.
pyramid
A three-dimensional figure
that has a polygon for its base and whose faces are triangles having a common
vertex.
Pythagorean Theorem
The theorem that relates
the three sides of a right triangle:
quadrant
One of the quarters of the
plane of the Cartesian coordinate system
quadrilateral
A polygon with 4 sides.
quotient
The answer to a division
problem.
radius
The distance from the
center to a point on a circle; the line segment from the center to a point on a
circle.
range
In statistics, the
difference between the largest and the smallest numbers in a data set.
rate
A ratio that compares
different kinds of units.
ratio
A pair of numbers that
compares different types of units.
rational number
A number that can be
expressed as the ratio of two integers.
ray
part of a line, with one
endpoint, and extending to infinity in one direction.
real numbers
The combined set of
rational numbers and irrational numbers.
reciprocal
The number which, when
multiplied times a particular fraction, gives a result of 1.
rectangle
A quadrilateral with four
90-degree angles.
reflection
A transformation resulting
from a flip.
regular polygon
A polygon in which all the
angles are equal and all of the sides are equal.
repeating decimal
A decimal in which the
digits endlessly repeat a pattern.
rhombus
A parallelogram with four
equal sides.
right angle
An angle whose measure is
90 degrees.
right triangle
A triangle that contains a
right angle.
root
The root of an equation is
the same as the solution to the equation.
rotation
A transformation in which
a figure is rotated through a given angle, about a point.
sample space
For an experiment, the
sample space includes all the possible outcomes.
Scale drawing
A drawing that is a
reduction or enlargement of the original.
scalene triangle
A triangle with three
unequal sides.
Scatter gram
A graph with points
plotted on a coordinate plane.
scientific notation
A method for writing
extremely large or small numbers compactly in which the number is shown as the
product of two factors.
set
A well-defined group of
objects
similar
Two polygons are similar
if their corresponding sides are proportional.
simplifying
Reducing to lowest terms.
skew lines
Lines that are not in the
same plane and that do not intersect.
slope
The steepness of a line
expressed as a ratio, using any two points on the line.
solution
The value of a variable
that makes an equation true.
sphere
A three-dimensional figure
with all points in space a fixed distance from a given point, called the center.
square
A quadrilateral with four
equal sides and four 90 degree angles
square root
The square root of x is
the number that, when multiplied by itself, gives the number, x.
statistics
The science of collecting,
organizing, and analyzing data.
stem and leaf plot
A technique for organizing
data for comparison.
straight angle
An angle that measures 180
degrees.
supplementary angles
Two angles are
supplementary if their sum is 180 degrees.
surface area
For a three-dimensional
figure, the sum of the areas of all the faces.
terminating decimal
A fraction whose decimal
representation contains a finite number of digits.
translation
A transformation, or
change in position, resulting from a slide with no turn.
transformation
A change in the position,
shape, or size of a geometric figure.
transversal
A line that intersects two
other lines.
trapezoid
A quadrilateral that has
exactly two sides parallel.
tree diagram
A diagram that shows
outcomes of an experiment.
triangle
A three-sided polygon.
unit price
Price per unit of measure.
variable
A letter used to represent
a number value in an expression or an equation.
vertex
The point on an angle
where the two sides intersect.
vertical angles
A pair of opposite angles
that is formed by intersecting lines.
volume
A measurement of space, or
capacity.
whole numbers
The set of numbers that
includes zero and all of the natural numbers.
x-axis
The horizontal axis in a
Cartesian coordinate plane.
x-intercept
The value of x at the
point where a line or curve crosses the x-axis.
y-axis
The vertical axis in a
Cartesian coordinate system.
y-intercept
The value of y at the
point where a curve crosses the y-axis.
zero
The additive identity; the
number that, when added to another number n, gives n.
zero property of multiplication
The product of zero and any
number is zero.