A

acute angle: an angle that is smaller than a right angle (less than 90 degrees)

adding: combining numbers

addition: the process of finding the sum of two or more numbers

always: 0n every occasion

analog: of or related to. For example, data that is represented by continuously measurable qantities such as length and width

analyze: to separate something into its basic parts

angle: two rays that share an endpoint. An angle is measured in degrees or radians.

approximation: an amount that describes another amount without being exactly equal to it

area: the measure, in square units, of the inside of any two-dimensional figure or surface of a 3-dimensional figure. arithmetic

arrangements: the order of how mathematical numbers, pictures and words are organized to make sense of the informationattribute or feature: a quality or characteristic of something

average: a single number that gives an idea about all the numbers in a set. Usually, the average is the mean, that is, the sum of numbers divided by the amount of numbers added up.

axes: the plural form of axis

axis: the number lines that are used to make a graph. There are usually two axes perpendicular to each other. The vertical axis is called y-axis and the horizontal axis is called the x-axis.

B

bar graph: a graph or diagram that uses vertical or horizontal bars to show information

C

calculate: figure out the answer to a number problem

calculator: a tool used to figure out the answer to a number problem

categorical data: values that are "words" that represent possible responses within a specific category

categories: the organization of numbers or mathematical information into groups

Celsius (C): the metric system scale for measuring temperature. Sometimes called "centigrade"

center: the point that is the same distance from all points in a circle, or vertexes in a regular polygon or a sphere

centimeter (cm): A metric unit of length equal to one hundredth of a meter

certain: the 100% likelihood that an event will occur

circle graph (pie graph): a graph in the shape of a circle that is divided into sections showing how the whole is broken into parts

classify: put into a category

clock face: the front of a clock showing time

closed shape: a shape whose sides are one continuous line or connected line segments, for example, a circle or a square

collect: to gather information or data

combination: putting two or more amounts, events or items together

common: shared

common factor: a factor that two or more numbers share. For example, 7 is a common factor of 14 and 35 because 7 is a factor of 14 (14=7x2) and 7 is a factor of 35 (35=7x5).

common fraction: any fraction whose numerator and denominator are whole numbers

common multiple: a number that is a multiple of two or more numbers. For example, 6, 12, and 24 are some of the common multiples of 2 and 3. compare: examine two or more quantities or figures for features that are similar and different

compass: a tool that is used to make circles or parts of circles

complementary angle: an angle that, when cut by a line into two angles, has a sum of 90 degrees.

composite number: a whole number with factors with more factors than just than 1 and itself (i.e., a whole number that is not prime). For example, the number 9 is a composite number because its factors are 1, 3 and 9.

consecutive: in order with none missing; one after the other

computation strategy; a method of figuring out the answer to a number problem

computation: the working through and solving of a math problem, using one or more operations

concave: curved inward

conclusion: the ending or result

cone: a three-dimensioal figure with one curved surface, one flat surface (usually circular), one curved edge and one vertex

congruent: exactly the same length, size and shape

constant rate of change: the non-changing frequency of an event

convex: curving outward

coordinate graph: graphical representation of pairs of related numerical values. The data are sorted into pairs of numbers with each pair associated with one person (for example, height and armspan of each person measured).

coordinate grid: A coordinate grid is a 2-dimensional system, in which a location is described by its distance from two perpendicular lines called axes (the plural for axis). The X axis is usually horizontal and the Y axis is usually vertical.

coordinates: an ordered pair of numbers that give the location of a point in a grid. The points are ordered as first x, then y: (x, y)correspond: to match closely or be equivalent to

counting number: a number used in counting objects, i.e., a number from the set 1, 2, 3, 4, 5,...

cube: (1) a regular solid with six congruent square faces; (2) the third power of a number, for example 10 x 10 x 10 = 1000

cubic centimeter: used to measure volume or capacity

cylinder: a three-dimensional figure with two parallel and congruent circles as bases, one curved surface, two curved edges, and no vertices.

D

data: values or information such as counts, ratings, measurements, or opinions that are gathered to answer questions

data analysis: studying and making sense of numerical information

decagon: A plane geometric figure having ten sides and ten angles

decimal place: a value of a decimal place, such as tenths, hundredths, thousandths, etc.

decimal: a form of a fraction based on the base ten place-value system. To write numbers as decimals, we use only 10 and powers of 10 as denominators. When we write 375/1000 as a decimal - 0.375 - the denominator of 1000 is understood. The digits to the left of the decimal point show whole numbers, and the digits to the right of the decimal point show a portions of a whole number.

decomposing: taking apart

deductive reasoning: a type of reasoning wherein the conclusion about particulars follows necessarily from general or universal basis

degree: (1) A unit for measuring angles; (2) a unit for measuring temperature in Celsius, Fahrenheit or Kelvin

denominator: the number written below the line in a fraction. In the fraction 3/4, 4 is the denominator.

diagonal: a line or line segment connecting two nonadjacent corners in a polygon

diameter: a straight line segment that passes through the center of a circle from one side to the other

difference: the number that remains after subtracting one number from another

digit: any of the 10 symbols: 1, 2, 3, 4, 5, 6, 7, 8, 9, 0

dimension: the length, width or height of a geometric figure

Discrete mathematics: the branch of mathematics that includes combinatorics, recursion, Boolean algebra, set theory, and graph theory.

divide: to separate into equal groups

dividend: the amount to be divided

divisibility: whether a number can be divided by another number evenly with no remainders

division: the operation of making equal groups

dodecagon: a twelve-sided polygon

E

endpoint: a point marking either end of a line segment

expression: a variable or combination of variables, numbers and symbols that represents a mathematical relationship. For example:

edge: the line segment where two faces of a solid figure meet

English unit: a unit of measurement also used in the United States, such as pounds, inches, gallons

equal: having the same value, for example, in measurement, quantity, shape

equation: a number sentence that uses an equal sign, showing the same value on both sides of the sign, for example 9+2=11.

equiangular: all angles have the same measure

equilateral triangle: a triangle whose sides are the same length

equilateral: all sides have the same length

equivalent fractions: fractions that are equal in value but have different numerators and denominators. For example, 2/3 and 14/21
are equivalent fractions.

equivalent: having the same value

estimate: a thoughtful and reasonable guess (noun); coming up with a thoughtful and reasonable guess (verb)

evaluate: to solve a math problem and arrive at the answer

even number: a multiple of 2. When you divide an even number by 2, the remainder is 0. Examples of even numbers are 2, 4, 6, 8, and 10.

exponential form: a way of writing a number using exponents

expanded notation: a way to write numbers so that the place value of each digit is shown. For example: 674= (6 x 100) + (7 x 10) + (4 x 1)

exponent: the small raised number that tells how many times a factor is used. For example, 5 to the third means 5x5x5.

extend: to continue a pattern or other numerical information

exterior angle: an angle on the outside of the polygon, for example:

F

face: the side of a three-dimensional shape. For example, a cube has six faces.

factor: one of two or more numbers that are multiplied together to get a product. For example, 13 and 4 are both factors of 52 because 13x4=52.

factor pair: two numbers multiplied together to get a product, for example, 2x5 whose product is 10

factorization (prime); a way to write a number as the product of prime factors, for example: 2 x 2 x 3 x 5 = 60

Fahrenheit: temperature scale.

Fibonacci numbers: the sequence of numbers beginning with 1, 1, in which each number that follows is the sum of the previous two numbers, i.e., 1, 1, (+) 2,(+) 3,(+) 5,(=) 8,(+) 13,(=) 21, 34, 55, 89, 144.

finite: countable

flat: a side with no curves

formula: a general rule for solving math problems

fractal: a curve or shape so irregular that its dimension (according to the technical definition of dimension) is a fraction, rather than an integer (whole number). Many interesting examples of fractals have the property of being self-similar, in the sense that portions of the fractal are similar in shape to magnified parts of itself at arbitrarily high rates of magnification.

fraction: a part of a whole number, with a numerator and a denominator

frequency: how often something occurs in an interval or a set of data

function: a mathematical relation that gives each object in a set exactly one value

G

gap: a space between data points on a graph

geometric or figural pattern: a sequence of symbols or geometric figures, for example, 1, 3, 5, etc.

geometric sequence (progression): an ordered list of numbers that has a common ratio, or number relationship, between consecutive terms, e.g., 2, 6, 18, 54º.(H) (ax 3)

geometric: having to do with geometry or the study of shapes, points angles, lines, and surfaces

geometry: the study of two and three-dimensional figures, such as rectangles and triangles, and points, lines, angles, shapes, surfaces and solids

graduated cylinder: a cylinder with measurements marked on the outside

graph: a way of organizing data, such as line plot, bar graph, line graph, pictograph(noun, verb); to plot data along the X and Y axes

greater than: if one number is greater than another number, the number is larger than the number being compared (>). If one number is less than another number, the number is smaller than the number being compared (<)."

greatest common factor: the highest number that is a factor of each of two numbers

grid lines: parallel horizontal lines and parallel vertical lines perpendicular to each other, and along the X-Y axes.

grid: a pattern of horizontal and vertical lines perpendicular to each other and aligned along the X-Y axes

grouping: a set of a data

H

height: usually a vertical dimension of shape or an object

hendecagon: an eleven-sided polygon

heptagon: a seven-sided polygon

hexagon: a six-sided polygon

I

if/ then: a way of organizing and explaining thoughts and proofs

impossible: cannot be done

inductive reasoning: a) The type of reasoning that uses inference to reach a generalized conclusion from particular instances; b) In mathematics, demonstration of the validity of a law concerning all the positive integers by proving that it holds for the integer 1 and that if it holds for an arbitrarily chosen positive integer k it must hold for the integer k+1; also called mathematical induction. (W)

improper fraction: a fraction whose numerator is larger than the denominator

integer: a number that is either a whole number or the negative of a whole number

interior angle: an angle inside a polygon or figure

intersect: a line that meets another line and crosses it

interval: the number of units between spaces on a graph scale

inverse relationship: A relationship between variables that move in opposite directions.

irrational number: a number that cannot be expressed as a quotient of two integers, e.g., the square root of 2. It can be shown that a number is irrational if and only if it cannot be written as a repeating or terminating decimal.

isosceles triangle: a triangle with at least two equal sides and least two equal angles

iterative pattern or sequence: a sequence or pattern formed by repeating the same procedure. For example, the Fibonacci sequence.

J

K

L

landmark number: (in TERC and other math curricula) a number that is frequently used and familiar to students, can be used to help estimate, round or solve math problems. Examples are 10, 25, 50, 100, 100, etc.

least common denominator: the least common multiple of two or more denominators

leftovers: a math curriculum term meaning remainders in division

length: the distance along a line from one point to anotherlikely: having at least a fifty percent chance of occurring

line graph: a set of data points on an X-Y grid, possibly with consecutive points, connected by line segments.

line: an infinite set of points forming a straight path extending in two directions

line of symmetry: a line that divides a figure into two congruent or equal halves that a mirror images of each other

line plot: a number line with dots, checks or other marks above it to show the number of times an event occurs

line segment: a part of a line defined by two end points

line symmetry: a geometric property

linear: having to do with a line

linear equation: a special kind of algebra equationliter: a liquid measure

lowest term: a fraction in its simplest form

M

mass: the amount of matter in an object, usually measured by balancing an object against a known mass (a scale)

matrix (plural matrices): a rectangular array of numbers or variables

maximum: the mostmean: the average of a particular set of numbersmeasurement: the dimension, quantity, or capacity found by measuring and expressed in units.

median: the middle of an ordered set of data

mental math: math done in your head, without paper, pencil or calculators

meter: a unit of length in the metric system

metric unit: a measuring unit within the metric system

midpoint: the point on a line segment that divides it into two congruent segmentsminimum: the least

mixed number: a combination of a whole number and a part of a whole number, such as a fraction or a decimal

mode: the category or numerical value that occurs most often

Multiple: The product of a given whole number and another whole number. For example, the first four multiples of 3 are 3, which is 3x1, 6, which is 3x2,9, which is 3x3, and 12,which is 3x4. Note that if a number is a multiple of 3, then 3 is a factor of the number. For example, 12 is a multiple of 3, and 3 is a factor of 12.

multiplication: the operation of repeated addition

N

natural numbers: the counting numbers such as 1,2,3,4,5,etc…

negative coordinates: a combination of negative numbers on a coordinate grid

negative number: numbers less than zero

Network: a) A figure consisting of vertices and edges that shows how objects are connected, b) A collection of points (vertices), with certain connections (edges) between them.

nonagon: a nine sided polygons

non-regular: refers to a polygon that does not have equal sides

number line: a diagram that represents numbers as points on a line

number pair: two numbers that are used to give the location of a point on a graph

number sentence: an equation for inequality with numbersnumeral: a symbol for a number, such as 4,7

numerator: the top number of a fraction; the number being divided by the denominator

Numeric pattern: A pattern composed of numerals.

Numerical data: values that are numbers such as counts, measurements, and ratings

O

observation: the act of noticing and studying patterns

obtuse: An angle that is greater than a right angle (greater than 90 degrees)

octagon: an eight-sided polygon

odd Number: a whole number that is not a multiple of 2. When an odd number is divided by 2, the remainder is 1. Examples of odd numbers are 1, 3, 5, 7, and 9.

operation: an action in mathematics, such as addition, subtraction (minus), multiplication, division0rder of 0perations 1. Do all of the operations inside parentheses, and/or above and below a fraction bar in the proper order, 2. Find the value of any powers or roots, 3. Multiply and divide from left to right, 4. Add and subtract from left to right. (H)

order: arranging numbers or quantities in a particular pattern

ordered pair: An ordered pair is a pair of numbers used to name a location on a grid. The first number tells the distance from the vertical or x axis. The second number tells the distance from the horizontal or y axis.

ordinal number: A number designating the place (as first, second, or third) occupied by an item in an ordered sequence. (W)

organize: to put together or arrange in an orderly systematic way

origin: the intersection of the X and Y axes in a coordinate plane. It is described by the ordered pair (0,0)

outcome: one of the possible events in a probability situation

Outlier: a number in a set of data that is much larger or smaller than most of the other numbers in the set

P

parallel line: In geometry, a line is parallel when it is always the same
distance apart from another line, and never intersects (=)

Parallelogram: A quadrilateral in which both pairs of opposite sides are equal and parallel. Both pairs of opposite angles are also equal.

Partition: A process of dividing an object into parts.

pattern: a predictable way that symbols repeat, increase or decrease. Examples: 10 x 4, 100 X 4, 1000 x 4

Pentagon: A five sided polygon

perimeter: the sum of the length of the sides of a figure

Percent: "Out of 100." A percent is a special decimal fraction in which the denominator is 100. When we write 68%, we mean 68 out of 100, 68/100, or 0.68. We write the percent sign (%) after a number to indicate percent.

perfect number: a whole number that is equal to the sum of its factors (excluding the number itself)

perpendicular: A line is perpendicular when it meets another line and forms a right angle (__I___).

pi: the ratio of the circumference of any circle to its diameter, approximately equal to 3.14 or 22/7

pictograph: a kind of graph that uses pictures or symbols to represent numbers.

place value: the value of the position of a digit in a number plane: In our Base 10 number system, whole numbers start with the ones place, then the tens place, then hundreds place and so on.

polyhedron: three dimensional figure in which all the surfaces are polygons

point: an exact location in space

Polygon: A closed, flat (two dimensional) shape whose sides are formed by line segments

positive number: numbers that are greater than zero"predict: In math, a student can foretell what might happen (predict) based
on data that s/he obtained."Prime factorization- The longest factor string for a number, composed entirely of prime numbers. For example, the prime factorization of 1001 is 7x11x13. The prime factorization of a number is unique except for the order of the factors.

Prime number: A number with only two factors, 1 and the number itself. Examples of primes are 11,17,53, and 101.

prism: a three dimensional figure that has two congruent end parallel faces that are polygons. The rest of the faces are
parallelograms

probability: the number of ways an event can occur divided by the total number of possible outcomes.product- the answer to a multiplication problem

proof: a method of constructing a valid argument, using deductive reasoningproportion: an equation that states that two ratios are equivalent, e.g., 4/8 = 1/2 or 4 : 8 = 1 : 2.

protractor: a tool used to measure angles

pyramid: three dimension shape four triangular faces and a square base

Pythagorean theorem: For any right triangle, the sum of the squares of the measures of the legs equals the square of the measure of the hypotenuse.

Q

Quadrilateral: A polygon with four sides.

quadrant: one-fourth of a coordinate grid

quadrilateral: a polygon with four sides

radius: the segment from the center of a circle to any point on the circle

quantity: amount

quotient: the answer to a division problem

R

radius: the segment from the center of a circle to any point on the circle

rate: ratio comparing two different units

range: the difference between the greatest and the least value in a set of data

random sampling: A small group of people or objects chosen from a large group

Random variable: A variable that is itself a function of the result of a statistical experiment in which each outcome has a definite probability of occurrence; also called variate.

reciprocal: two numbers whose product is one (1)

ray: a part of a line that has one end point and extends indefinitely in one direction

ratio: a comparison of two numbers or quantities, e.g., 4 to 7 or 4 : 7 or 4/7.

rational number: a number that can be written as the ratio of an integer to a counting number; or, a number that can be expressed as a ratio a/b where a and b are integers and b 0, e.g., 0.5, 3/5, -3, 8, 3-9/10.

real number: number from the set of numbers consisting of all rational and all irrational numbers.

reasonable: makes sense

rectangle: a parallelogram with all right angles, as shown below. Squares are a special type of rectangle, with four equal sides.

rectangular array: an arrangement of squares or other objects in vertical and horizontal rows and columns

reduce: put fraction into its simplest form

rectangular prism: a 3-dimension figure with six rectangular faces

reflection: a type of transformation that flips points about a line, called the line of reflection. Taken together, the image and the pre-image have the line of reflection as a line of symmetry. A reflection creates a mirror image.

regroup: use place value to think of a number in a different way that makes calculating easier

regular polygon: a polygon that has all of its sides equal and all of its angles equal.

relation/ relationship: connections among two or more numbers or geometric figures

repeating decimal: a decimal that has an infinitely repeating sequence of digits

remainder: what is left in a division problem that can't continue to be distributed by the divisor

repeated addition: adding a number to itself a certain number of times

revolution: one turn of 360 degrees around a point

rhombus: a parallelogram with four equal sides

right angle: A right angle is an angle that measures exactly 90 degrees.

right triangle: a triangle with one right anglerotation: a type of transformation that turns a figure about a fixed point, called the center of rotation

rotational symmetry: a line of symmetry around a fixed point

sample: a number of people or objects chosen from a given population to represent the entire group

round: (verb) replacing a number with a number that tells about how many, rather than exactly how many. Example: 23 rounded to the nearest 10 is 20

row and column: an arrangement that is horizontal (row) and vertical (column)

rubric: an explanation

Random sampling: A smaller group of people or objects chosen from a larger group or population by a process giving equal chance of selection to all possible people or objects. (H)

Random variable: A variable that is itself a function of the result of a statistical experiment in which each outcome has a definite probability of occurrence; also called variate. (W)

Ratio: A comparison of two numbers or quantities, e.g., 4 to 7 or 4 : 7 or 4/7.

Rational number: A number that can be written as the ratio of an integer to a counting number; or more formally, a number that can be expressed as a ratio a/b where a and b are integers and b 0, e.g., 0.5, 3/5, -3, 8, 3-9/10.

Real number: A number from the set of numbers consisting of all rational and all irrational numbers.

Rectangle: A parallelogram with all right angles, as shown below Squares are a special type of rectangle.

Recursive pattern or sequence: A pattern or sequence wherein each successive term can be computed from some or all of the preceding terms by an algorithmic procedure.

Reflection: A type of transformation that flips points about a line, called the line of reflection. Taken together, the image and the preimage have the line of reflection as a line of symmetry.

Regular Polygon: A polygon that has all of its sides equal and all of its angles equal. The hexagon below is regular, but the pentagon is not regular, because its side and its angle are not equal.

Right angle: An angle that measure 90 degrees. All of the vertices in a rectangle are right angles.

Rotation: A type of transformation that turns a figure about a fixed point, called the center of rotation.

S

scale: the relation of length on a map, drawing or model to represent the length in reality

scalene: all unequal sides

scientific notation: a widely used floating-point system in which numbers are expressed as products consisting of a number between 1 and 10 multiplied by an appropriate power of 10, e.g., 562 = 5.62 x 102.

septagon: a seven-sided polygon

sequence, progression: a set of elements ordered so that they can be labeled with consecutive positive integers starting with 1, e.g., 1, 3, 9, 27, 81. In this sequence, 1 is the first term, 3 is the second term, 9 is the third term, and so on. (W)

set: a group

side: one of the line segments that make up the boundaries of a polygon

similar: having the same shape, though not necessarily the same sizesimplify: reduce to lowest terms

skip count: counting by a particular number

slope: a specific slant of a line

solve: figure out a solution or answer to a problem

speed: the rate of growth or a moving object

sphere: a three-dimensional figure made up of all points that are equally distant from a point called the center. ( like a ball)

Square: A quadrilateral with four equal sides and four right angles

square centimeter: a centimeter that measures area 1cmx1cm

Square number: the product of a number multiplied by itself. 9 is a square number because it is the product of 3x3.

Square root: the inverse or reverse of sqaring a number. For example, the square root of 100 is 10, because 10 x 10 = 100.

subtraction: finding the difference between two numbers. For example, 6 is the difference between 9 and 3.

Sum: the answer to an addition problem. The sum of 32 and 46 is 78.

supplementary angle: An angle that, when bisected by a line into two angles, has a sum of 180 degrees.

surface area: the total area of the faces and curved surfaces of a solid figuresurvey- data collected from responses to a question or group of question

symbol/symbolic: represents an operation or an idea

symbol: plus sign (+), minus sign (-), multiplication sign (x), division sign (÷ ; /) and equal sign (=). Other symbols include greater than (>), less than (<).

symmetrical: a design or arrangement that is the same on one side as it is on the other

T

table: a systemic arrangement of data in rows or columns for ready reference.
tally: a mark used to keep track of items when counting.thermometer: a tool used to measure temperature

Translation: A type of transformation that moves every point by the same distance in the same direction, e.g., in a geographic map, moving a given distance due north.trapezoid: a quadrilateral with two opposite parallel sides

trapezoid: a quadrilateral with two opposite parallel sides

tree diagram: breaking a large number into its factor pairs

Triangle: three sided polygon

turn: see rotation

two-dimensional: an object having length and width

U

unit: A precisely fixed quantity used to measure.

V

Valid: a) Well-grounded or justifiable; being at once relevant and meaningful, e.g., a valid theory; b) Logically correct. (W)

value: the worth of a numberVariable A letter or symbol used to represent one or more numbers in an expression, equation, inequality, or matrix. (H)

Vector: A quantity that has magnitude and direction. A vector is typically represented by a directed line segment, whose length represents the magnitude and whose orientation in space represents the direction. (W)

Venn diagram: A diagram that is used to show relationships among sets.

Vertex- The corner of a polygon; all angles have vertices.

vertices: the plural of vertex

Volume: the number of three-dimensional or cubic units it takes to fill a solid

W

weight: A measure of how heavy an object is.

Whole number: A number that is either a counting number or zero.

X

x-axis: on a coordinate grid, the horizontal axis

x-coordinate: in an ordered pair, the value that is written first. In (2,3) 2 is the x-coordinate

Y

y-axis: on a coordinate grid, the horizontal axis

y -coordinate: in an ordered pair, the value that is written second. In (2,3) 3 is the y-coordinate

Z