A - D

Math Vocabulary

absolute value

The absolute value of a

positive number is the number

itself.

absolute value of -6 is 6

absolute value of 3 is 3

abundant number

A number in which the sum of all its proper factors is greater than the

number itself.

12 is an abundant number

Because the sum of its proper factors is

1 + 2 + 3 + 4 + 6 = 16

16 is greater than 12

acre

A unit of area equal to

43,560 square feet.

addend

One of two or more numbers

that are added.

addends

14 + 15 + 6 = 35

sum

addition

A mathematical operation based on

putting together two or more quantities.

+ 2 + 3 = 5

addition fact

Two 1-digit numbers and their

sum.

9 + 7 = 16digit

sum

add

additive inverses

Two numbers whose sum is 0.

The additive inverse of a number

is also called its opposite.

3 +(-3)=0

additive inverse of 3 is -3

additive inverse of -3 is 3

adjacent angles

Two angles with a common side that do not otherwise

overlap.

algebraic expression

An expression that contains a variable.

7x + 3 = 24

x + 5 = 10

4 + 6 X 3 ÷ 2 – 1 =

algorithm

A set of step-by-step instructions for doing something, such as

carrying out a computation or solving

a problem.

A.M.

It means “before the middle of the day” from midnight to

noon.

A.M. = ante meridiem

analog clock

A clock that shows the time by the position of the hour and minute hand.

hour

minute

angle

A figure that is formed by two rays

or two line segments with a

common endpoint.

apex

In a pyramid or cone, the vertex that is opposite

the base.

arc

Part of a circle from one point on

the circle to another.

area

The measure of a bounded

surface.

area

The measure of the surface

inside a closed

boundary.

A=1xW

area model

A model for multiplication problems, in which the length and width of a

rectangle represents the factors and the area

represents the product.

3 X 5 = 15

arithmetic fact

Any of the basic addition and multiplication

relationships and the corresponding

subtraction and division relationships.

9 + 7 = 1616 – 9 = 7

2 X 3 = 66 ÷ 2 = 3

arm span

The distance from fingertip to

fingertip of a person’s

outstretched arms.

array

A rectangular arrangement of

objects in rows and columns.

}column

{row

arrows

The links representing the rule that determines which numbers go in the frames of a Frames-and-

Arrows diagram.

Rule

+ 5

arrow

arrow rule

5 10 15 20

arrow path

A route to follow on a

number grid.

64

64 65 5656

56

arrow rule

The operation that determines the number

that goes in the next frame in a Frames-and-

Arrows diagram.

Rule

+ 3

arrow

arrow rule

5 8 11 14

associative

property

A property of addition and multiplication (but not of subtraction or

division) that says that changing the grouping of

the elements being added or multiplied will not change the sum or

product.

(4+3)+7=4+(3+7)

attribute

A feature of an object or a

common feature of a set of objects.

colorsizeshapenumber of sides

average

A typical or middle value for a set of numbers which is

found by adding the numbers in the set

and dividing the sum by the number

of numbers.

2, 4, 5, 9, 10 = 30 30 ÷ 5 = 6

The average is 6.

axis

Either of the two number lines used to

form a coordinate

grid.

ballpark estimate

A rough estimate used as a check on the

reasonableness of an answer or when an exact figure is not

necessary.

27+39=66

30+40=70

bank draft

A written order for the exchange of money. $1000 bills are no

longer in use, so bank drafts are used instead.

bar graph

A graph that shows the relationships

among variables by the use of bars to

represent quantities.

base

1. Any side of a polygon, usually used, along with

the altitude perpendicular to it, for

computing area. 2. The flat face of faces

that define the shape when classifying

polyhedrons.

base

base ten

The familiar numeral system, consisting of the

ten digits 0,1,2,3,4,5,6,7,8,9

and a method of assigning values to

these digits depending on where they appear in

a number.

base 10 shorthan

d

A system to represent base 10

blocks.

....

. ..

base of a parallelogr

am

One of the sides of a parallelogram; also the length of this

side.

base of a polygon

The side on which the polygon “sits”; the side that is perpendicular to

the height of the polygon.

base of a polyhedron

The “bottom” face of a polyhedron; the

face whose shape is the base for

classifying a prism or pyramid.

base of a rectangle

One of the sides of a rectangle; also length of this side. The length of the side perpendicular

to the base is the height of a rectangle.

base of 3-dimensional

figure

One face or a pair of faces on the figure. The height is

the length of a line segment drawn

perpendicular to a base of the figure that extends

from the base to the opposite face or vertex.

base of a triangle

One of the sides of a triangle; also, the length of

its side. The shortest distance between the base and the vertex opposite the

base is the height of a triangle.

benchmark

An important or memorable count or

measure that can be used to evaluate the reasonableness of other counts or

measures.

big cube

The term for the 10 cm by 10 cm base

10 block. A big cube is worth 1,000 cm

cubes.

bisect

To divide a segment, angle, or

figure into two parts of equal measure.

capacity

A measure of how much a container can hold, usually in units

such as quarts, gallons, cups, or liters.

Celsius

The temperature scale on which 0 is the

temperature that pure water freezes and 100 it

boils. Celsius scale is used in the metric

system.

0

0

centimeter (cm)

In the metric system a unit of length equivalent to 10 millimeters,(1/10)

of a decimeter, and (1/100) of a meter.

centimeter cube

The term for the smallest of the base-10 blocks,

measuring 1 cm on each edge.

chance

The possibility of an outcome in an

uncertain event.

change diagram

A diagram used to represent situations in which quantities are either increased or

decreased.

Start

14

End

9

Change

-5

14 – 5 = 9

circle

The set of all points in a plane that are equally distant from a given

point in the plane called the center of the circle.

circle

The set of all points in a plane that are equally distant from a given

point in the plane called the center of the circle.

circle graph

A graph in which a circle and its interior are

divided into parts to represent the pairs of a set of data. The circle

represents the whole set of data.

circumference

The distance around a circle or

sphere.

Class Data Pad

A large pad of paper where data collected by the class can be stored

for use (and review) throughout the year.

column

A vertical arrangement of

objects or numbers in an array or table.

}column

{row

column-addition method

A method for adding numbersin which the addends’ digits are first added in each place-value column

separately, and then 10-for-1 trades are made until each column has only one digit. Lines are drawn to separate

the place value columns.

common

Shared by two or more numbers. A common

denominator of two fractions is any non zero number that

is a multiple of the denominators of both

fractions. A common factor of two numbers is any

number that is a factor of both numbers.

commutative

property

A property of addition and multiplication (but not of subtraction or

division) that says that changing the order of the elements being added or multiplied will not change

the sum or product.

8+7=15 7+8=15

comparison diagram

A diagram used to represent situations in which two quantities

are compared.

Quantity

12

Quantity Quantity

9 ?

12 = 9 + ?

compass

a) A device for drawing circles.

b) A navigational device that points to Earth's magnetic North Pole.

complementary angles

Two angles whose

measures total 90.

o

composite number

A whole number that is more

than two whole-number factors.

concave (no convex)

polygon

A polygon in which at least one vertex is “pushed in.”

concentric circles

Circles that have the same center

but radii of different lengths.

congruent

Two figures that are identical—the same size

and shape.

cone

A 3-dimensional shape having a circular base, a

curved surface, and one vertex, called the

apex.

base

curved surface

apex

consecutive

Following one another in an uninterrupted

order.

A, B, C, D, E

6, 7, 8, 9, 10

consecutive angles

Two angles that are “next to each

other”; they share a common side.

constant

A number used over and over with an

operation performed on many numbers.

3 X 1 = 34 X 1 = 45 X 1 = 5

conversion fact

convex polygon

A polygon in which all vertices

are “pushed outward.”

coordinate

A number used to locate a point on a

number line, or either of two numbers used to locate a point on a

coordinated grid.

coordinate

grid

A device for locating points in a plane by means of ordered number

pairs or coordinates.

corner

The point at which the rays or line segments of an angle, side of a

polygon, or other edge of a polyhedron

meet.

corner

corresponding angles

Any pair of angles in the same relative position

in two figures, or in similar locations in

relation to a transversal intersection two lines.

corresponding sides

Any pair of sides in the same

relative position in two figures.

counting numbers

The numbers used to count things.

Sometimes 0 is included with the

counting numbers.

{1, 2, 3,4, ...}

counting numbers

The numbers used to count things. The set of counting numbers is {1,2,3,4,…}. All

counting numbers are integers and rational numbers, but not all integers or rational

numbers are counting numbers.

counting numbers

The numbers used to count things. All

counting numbers are integers and rational numbers, but not all integers or rational

numbers are counting numbers.

{1, 2, 3,4, ...}

cubes

A polyhedron with six square faces.

One regular polyhedron.

cubic centimeter

(cm )

A metric unit of volume; the volume of a cube 1 centimeter on a side. 1

cubic centimeter is equal to 1 milliliter.

3

cubic unit

A unit used in a volume and

capacity measurement.

cubit

An ancient unit of length, measured from the point of the elbow

to the end of the middle finger.

cup

In the U.S. customary system, a unit of capacity equal to 8 fluid ounces; ½ pint.

curved surface or

face

A surface which does not lie in a

plane.

customary system

The measuring system used most often in

the U.S.

lengthinchesfeetyardsmiles

capacityouncescupspintsquartsgallonstea spoons

table spoons

weightouncespoundstons

customary system

The measuring system used most often in

the U.S.

lengthinchesfeetyardsmiles

capacityouncescupspintsquartsgallonstea spoons

table spoons

weightouncespoundstons

cylinder

A 3-dimensional shape having a

curved surface and parallel circular or

elliptical bases that are the same size.

data

Information gathered by observing,

counting, or measuring.

deci-

Prefix meaning

one-tenth.

.10

decimal

A number written in standard

notation, usually one containing a decimal point.

$24.45 1 2

= .50

decimal point

The mark that separates the whole

number from the fraction in decimal

notation. It separates the dollars from the

cents.

$24.45 1 2

= .50

decimal point

The period which separates the

whole number from the fraction in

decimal notation.

$24.45 1 2

= .50

decimeter (dm)

Metric unit measuring length equivalent to 1/10 of a meter or 10

centimeters.

deficient number

A number for which the sum of all the proper factors is

less than the number.

10 is a deficient number

the sum of its proper factors is1 + 2 + 5 = 8

8 is less than 10

degree ( )

A unit for measuring

temperature.

21o

32o

degree ( )

A unit of measure for angles; based on dividing a circle into

360 equal parts.

denominator

The number written below the line in a

fraction.

14

23

34

denominator