a.m.

A time between (12:00) midnight and (12:00) noon.

add

To combine, put together two or more quantities.

addend

Any number being added.

Additive Identity Property of 0

When you add zero to a number, the sum is that same number.

algorithm

A step-by-step method for computing.

analog clock

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

angle

Two lines that meet at a common point.

area

The measure, in square units, of the inside of a plane figure.

area model

A model of multiplication that shows each place value product within a rectangle drawing.

arithmetic patterns

A sequence of numbers in which the difference between any two consecutive numbers is the same.

1, 5, 9, 13... is an arithmetic sequence pattern. The difference between any two consecutive numbers is 4.

1, 5, 9, 13... is an arithmetic sequence pattern. The difference between any two consecutive numbers is 4.

array

An arrangement of objects in equal rows.

Associative Property of Addition

Changing the grouping of three or more addends does not change the sum.

Associative Property of Multiplication

Changing the grouping of three or more factors does not change the product.

attribute

A characteristic of an object, such as color, shape, size, etc.

bar graph

A graph that uses the height or length of rectangles to compare data.

bar model

A model that uses bars to represent known and unknown quantities and the relationship between these quantities.

base-ten numeral form

A common way of writing a number using digits.

The value of a numeral depends on where it appears in the number.

also known as**standard form**

The value of a numeral depends on where it appears in the number.

also known as

base-ten numerals

Any of the symbols 0, 1, 2, 3, 4, 5, 6, 7, 8, or 9. The symbols can represent any amount based on a place value system of grouping by tens.

also known as**digits**

also known as

centimeter

A metric unit of length equal to 0.01 of a meter.

100 cm = 1 m

100 cm = 1 m

closed shape

A figure that begins and ends at the same point.

column

A vertical arrangement of numbers or information in an array or table.

Commutative Property of Addition

Changing the order of the addends does not change the sum.

Commutative Property of Multiplication

Changing the order of the factors does not change the product.

compare

To decide if one number is greater than, less than, or equal to another number.

compatible numbers

Numbers that are easy to compute mentally and are close in value to the actual numbers.

Compatible numbers can be used when estimating.

Compatible numbers can be used when estimating.

compose

To put together 2 or more shapes to create a new shape.

compose

To put together smaller numbers to make larger numbers.

congruent

Having exactly the same size and shape.

counting number

A whole number that can be used to count a set of objects. Counting numbers do not include 0.

(Example: 1, 2, 3, 4...)

(Example: 1, 2, 3, 4...)

customary system

A system of measurement used in the U.S. The system includes

units for measuring length, capacity, and weight.

units for measuring length, capacity, and weight.

data

A collection of information.

decagon

A polygon with ten sides.

decompose

To separate into components or basic elements.

denominator

The quantity below the line in a fraction. It tells how many equal parts are in the whole.

difference

The amount that remains after one quantity is subtracted from another.

digit

Any of the symbols

0, 1, 2, 3, 4, 5, 6, 7, 8, or 9.

0, 1, 2, 3, 4, 5, 6, 7, 8, or 9.

digital clock

A clock that shows the time with numbers of hours and minutes, usually separated with a colon. (:)

Distributive Property

When one of the factors of a product is a sum, multiplying each addend before adding does not change the product.

divide

To separate into equal groups and find the number in each group or the number of groups.

dividend

A number that is divided by another number.

divisor

The number by which another number is divided.

eighths

The parts you get when you divide something into eight equal parts.

elapsed time

The amount of time that has passed.

(A time interval)

(A time interval)

endpoint

A point at either end of a line segment, or a point at one end of a ray.

equal

Having the same value.

equal groups

Groups that contain the same number of objects. Whenever you divide, you separate items into equal groups.

equal parts

Parts of an object or group that have been divided equally into pieces.

equation

A mathematical sentence with an **equals sign**. The amount on one side of the equals sign has the same value as the amount on the other side.

equivalent fractions

Fractions that have the same value.

estimate

To find a number close to an exact amount; an estimate tells about how much or about how many.

evaluate

To find the value of a mathematical expression.

even number

An even number can be shown as 2 equal parts.

An even number has 0, 2, 4, 6, or 8 in the ones place.

An even number has 0, 2, 4, 6, or 8 in the ones place.

expanded form

A way to write numbers that shows the place value of each digit.

experiment

An activity that has two or more possible results.

Example: pulling marbles from a bag

Example: pulling marbles from a bag

expression

A mathematical phrase without an equal sign.

fact family

A group of related facts that use the same numbers.

Also called related facts.

Also called related facts.

factor

The whole numbers that are multiplied to get a product.

foot

A customary unit of length.

1 foot = 12 inches.

1 foot = 12 inches.

fourths

The parts you get when you divide something into 4 equal parts.

fraction

A way to describe a part of a whole or a part of a group by using equal parts.

fraction greater than one

A fraction with the numerator greater than the denominator.

fraction less than one

A fraction with the numerator less than the denominator.

frequency table

A table that uses numbers to record data.

gram

The standard unit of mass in the metric system.

greater than

Greater than is used to compare two numbers when the first number is larger than the second number.

half hour

A unit of time equal to 30 minutes.

halves

The parts you get when you divide something into 2 equal parts.

hexagon

A polygon with six sides.

horizontal bar graph

A graph that uses length of rectangles to compare data.

hour

Units of time.

1 hour = 60 minutes.

24 hours = 1 day.

1 hour = 60 minutes.

24 hours = 1 day.

hundreds

The value of a digit that is the third position from the right when describing whole number place value.

inch

A customary unit of length.

12 inches = 1 foot.

12 inches = 1 foot.

intersecting lines

Lines that cross at a point.

interval

The distance between two points.

inverse operations

Operations that undo each other.

key

A part of a map, graph, or chart that explains what the symbols mean.

kilogram

A metric unit of mass equal to 1000 grams.

length

How long something is. The distance from one point to another.

Length is measured in units such as inches, feet, centimeters, etc.

Length is measured in units such as inches, feet, centimeters, etc.

less than

Less than is used to compare two numbers when the first number is smaller than the second number.

line

A set of connected points continuing without end in both directions.

line plot

A diagram showing frequency of data on a number line.

line segment

A part of a line with two endpoints.

liter

The basic unit of capacity in the metric system.

1 liter = 1,000 milliliters.

1 liter = 1,000 milliliters.

mass

The amount of matter in an object. Usually measured by comparing with an object of known mass. While gravity influences weight, it does not affect mass.

meter

A standard unit of length in the metric system.

metric system

A system of measurement based on tens. The basic unit of capacity is the liter. The basic unit of length is the meter. The basic unit of mass is the gram.

midnight

12:00 at night

minute

One sixtieth of an hour or 60 seconds.

multiple

A product of a given whole number and any other whole number.

Multiplicative Identity Property of 1

If you multiply a number by one, the product is the same as that number.

multiply

The operation of repeated addition of the same number.

noon

12:00 in the day

number line

A diagram that represents numbers as points on a line.

numerator

The number written above the line in a fraction. It tells how many equal parts are described in the fraction.

octagon

A polygon with eight sides.

odd number

An odd number cannot be shown as two equal parts.

An odd number has 1, 3, 5, 7, or 9 in the ones place.

An odd number has 1, 3, 5, 7, or 9 in the ones place.

ones

A single unit or object.

open shape

A figure that does not begin and end at the same point.

order

A sequence or arrangement of things.

To order fractions, compare two fractions at a time.

To order fractions, compare two fractions at a time.

Order of Operations

A set of rules that tells the order in which to compute.

p.m.

The time between (12:00) noon and (12:00) midnight.

parallel lines

Lines that are always the same distance apart.

parallelogram

A quadrilateral with two pairs of parallel and congruent sides.

parentheses

Used in mathematics as grouping symbols for operations. When simplifying an expression, the operations within the parentheses are performed first.

partition

An action to divide shapes into smaller parts.

partitive division

A division problem where the number of objects in each group is unknown.

How many in each group?

How many in each group?

pattern

repeating or growing sequence or design. An ordered set of numbers or shapes arranged according to a rule.

pentagon

A polygon that has five sides.

perimeter

The distance around a figure.

perpendicular lines

Two intersecting lines that form right angles.

picture graph

A graph that uses pictures or symbols to show data.

place value

The value a digit has because of its place in a number.

plane figure

A two-dimensional figure.

point

The exact location in space represented by a dot.

polygon

A closed plane figure made by line segments.

product

The answer to a multiplication problem.

quadrilateral

A four sided polygon.

quarter hour

A unit of time worth 15 minutes.

quotative division

A division problem where the number of groups is unknown.

How many groups?

How many groups?

quotient

The answer to a division problem.

ray

A part of a line that has one endpoint and goes on forever in one direction.

reasonableness

An answer that is based on good number sense.

rectangle

A quadrilateral with two pairs of congruent, parallel sides and four equal angles.

rectilinear figure

A polygon where all angles are right angles.

regroup

To rearrange the formation of a group.

related facts

Related addition and subtraction facts or related multiplication and division facts.

Also called**fact family**.

Also called

remainder

In whole number division, when you have divided as far as you can without using decimals, what has not been divided yet is called the remainder.

repeated addition

Adding equal groups of objects to find the total amount of objects.

repeated subtraction

Subtracting equal groups to find the total amount of groups.

rhombus

A quadrilateral with all four sides equal in length.

right angle

An angle that forms a square corner.

round a whole number

To find the nearest ten, hundred, thousand, (and so on).

row

A horizontal arrangement of numbers or information in an array or table.

scale (on a graph)

The numbers that show the units used on a graph.

sequence

A set of numbers arranged in a special order or pattern.

side of a polygon

Any of the line segments that form a polygon.

sixths

The parts you get when you divide something into six equal parts.

skip count

Counting by a given number greater than 1.

square

A parallelogram with four equal angles AND four equal sides.

square unit

A unit, such as square centimeter or square inch, used to measure area.

standard form

The common or usual way of writing a number using digits.

Also called**base-ten numeral form**.

Also called

subtract

An operation that gives the difference between two numbers.

Subtraction can be used to compare two numbers, or to find out how much is left after some is taken away.

Subtraction can be used to compare two numbers, or to find out how much is left after some is taken away.

sum

The answer to an addition problem.

survey

A way to gather data by asking questions.

tally table

A table that uses tally marks to record data.

tens

Sets of ten ones.

Examples: 10, 20, 30, 40, 50, 60, 70, 80, or 90

Examples: 10, 20, 30, 40, 50, 60, 70, 80, or 90

thirds

The parts you get when you divide something into 3 equal parts.

tiling

A pattern of shapes repeated to fill a plane. The shapes do not overlap and there are no gaps.

time interval

A duration of a segment of time.

Also known as**elapsed time**

Also known as

trapezoid

A quadrilateral with one pair of parallel sides and one pair of sides that are not parallel.

triangle

A polygon with three sides and three angles.

two-dimensional

Having length and width. Having area, but not volume.

Also called a**plane figure**.

Also called a

unit fraction

A fraction that has 1 as its numerator.

A unit fraction names 1 equal part of a whole.

A unit fraction names 1 equal part of a whole.

unit square

A square with side lengths of 1 unit each. It has an area of 1 square unit.

variable

A letter or symbol that represents a number.

Venn diagram

A drawing with circles or rings to show how sets of objects are related.

vertex (plural - vertices)

A point at which two or more sides of a geometric figure meet.

vertical bar graph

A graph that uses height of rectangles to compare data.

volume (liquid)

The number of cubic units it takes to fill a figure.

whole

All of an object, a group of objects, shape, or quantity.

whole numbers

Whole numbers are zero and the counting numbers 1, 2, 3, 4, 5, 6, and so on.

If a number has a negative sign, a decimal point, or a part that's a fraction, it is not a whole number.

If a number has a negative sign, a decimal point, or a part that's a fraction, it is not a whole number.

width

One dimension of a 2-dimensional or 3-dimensional figure.

word form

A way of using words to write a number.

Also called**number names**.

Also called

yard

A customary unit of length.

1 yard = 3 feet

or 36 inches

1 yard = 3 feet

or 36 inches

Zero Property of Multiplication

The product of any number and zero is zero.