• Third Grade Everyday Math Vocabulary

    Please note that the words for each unit are listed by the order in which they are covered, not alphabetically.

    Unit One: Routines, Review, & Assessment

    unit –a symbol that tells what a number means like feet,

            degrees, minutes, etc.

    number grid –a table that lists numbers in order

    data base- a collection or set of information

    template- a stencil used for drawing geometric shapes

    frames and arrows- a diagram used to show a number pattern or


    tally chart –a chart that uses tally marks to show how many times

     each value appears in a set of data

    bar graph –a graph that uses bars to represent numbers in the


    name collection box –a place to write equivalent names for the same number

    estimation –an answer that is close to the exact answer

    calculate –to figure out an answer using numbers  

    Unit Two: Adding and Subtracting Whole Numbers

    fact family/ number family- related addition and subtraction

            facts or related multiplication and division facts  

    difference- the answer to a subtraction problem  

    fact extension- a method of using a math fact to solve a bigger

            problem like if 5+7=12 then 50+70=120  

    function machine –an imaginary machine used to change numbers

            from input to output according to a given rule  

    parts-and-total diagram –a diagram that is used to keep track of

     the numbers and missing information in problems where

    two parts are combined to find a total  

    number model –equation showing how a number story is solved  

    change diagram –a diagram used to keep track of numbers and

            missing information in a number story in which an amount

            is increased or decreased  

    ballpark estimate –a good rough estimate used when you don’t

            need an exact answer or to check if an answer makes


    addend –a number that is added in an addition problem  

    sum- the answer to an addition problem  

    Unit Three: Linear Measures and Area

    inch- unit of measure representing 1/12 of a foot  

    line segment- a strait path between two endpoints 

    centimeter- a unit of measure representing 1/100 of a


    millimeter –a unit of measure representing 1/1000 of a


    perimeter –the distance around a shape  

    polygon –a closed figure on a flat surface that is made up of

            line segments joined end-to-end; the line segments of a

            polygon may not cross  

    area –the amount of surface inside a shape measured in square


    square foot –a unit of surface area measuring 1 ft X 1 ft  

    circumference –the distance around a circle (its perimeter)  

    diameter –a line segment that goes through the center of a circle

            and has endpoints on the circle  

    Unit Four: Multiplication & Division

    multiplication –the operation of putting together numbers of

            equal groups 

    array- an arrangement of objects in rows and columns 

    factor- any of the numbers that are multiplied to find a product;

            a number that divides another number evenly;

            8 is a factor of 24 

    product- the answer to a multiplication problem 

    quotient- the answer to a division problem 

    dividend- the number to be divided in a division problem 

    divisor- the number being divided into the dividend in a division


    remainder- the amount left over when things are divided or

     shared equally 

    square numbers- numbers that result from multiplying 2 of the

            same factors: 2,4,9,16,25,36…

    Unit Five: Place Value in Whole Numbers & Decimals

     place value- the system for writing numbers in which the

    value of a digit depends on its place in the number 

    greater than- > bigger than, the arrow opens to “eat”

              the bigger number 

    less than- , smaller than, the arrow points at the smaller


    pie graph- a circular graph that represents amounts as

              different size pieces of “pie” 

    decimals- parts of a whole represented in tenths,

    hundredths, thousandths, etc.. 

    tenths- a decimal representing a part of a whole where

              ten parts would equal one whole 

    hundredths- a decimal representing a part of a whole

              where 100 parts would equal one whole 

    thousandths- a decimal representing a part of a whole

              where 1000 parts would equal one whole 

    decimeter- a unit equal to 10 centimeters or 1/10 of a


    Unit Six: Geometry

    line segment –a straight path between two endpoints  

    end point –the point at the end of a ray or line segment  

    ray- a straight path that has one end point and goes on


    line- a straight path that goes on forever in both directions  

    parallel- always the same distance apart and never meeting or

            crossing each other, no matter how far extended  

    intersect –to meet or cross  

    angle- a figure that is formed by two rays or two line segments

             that have the same end point  

    right angle- a 90o angle, its sides form a square corner  

    vertex- the point where the rays of an angle or the sides of

            a polygon or the sides of a polyhedron meet  

    equilateral –having sides of equal length  

    quadrangle –a polygon that has 4 sides and 4 angles, the same

            as a quadrilateral  

    square- a rectangle whose sides are all the same length  

    rhombus- a parallelogram with all 4 sides the same length

    parallelogram- a four-sided polygon that has 2 pairs of

            parallel sides; the parallel sides are also the same length  

    rectangle –a parallelogram whose corners are all right angles  

    trapezoid- a four-sided polygon with exactly one pair of parallel


    adjacent sides- sides that share a vertex  

    kite- a four-sided polygon with 2 pairs of equal sides; the equal

     sides are next to each other; the four sides cannot all have

    the same length  

    degree- a unit of measure for angles; also a unit of measure

            for temperature  

    symmetry- figure with at least one line that can divide the

            figure into 2 parts look exactly alike but are pointing in

    different directions; if you fold the figure in half the two

    halves match exactly  

    congruent figures- figures that have the same shape and size  

    polyhedron- a geometric solid whose surfaces or faces are all

            formed by polygons  

    cone- a solid that has a circular base and a curved surface that

            ends at a point called the apex  

    cylinder- a solid that as 2 circular bases that are parallel and the

            same size; the bases are connected by a curved surface  

    sphere- a solid with a curved surface that looks like a ball  

    pyramid- a solid that has one base that is a polygon; all the

            other sides (or faces) are triangles that come together

            at a point called a vertex or apex  

    prism- a solid that has a parallel bases that are polygons with the

     same size and shape; all other faces are parallelograms  

    base- a name used for the side of a polygon and a face of a

    three-dimensional figure  

    face- a flat surface on the outside of a solid  

    edge- a line segment or curve where the edges of a solid meet  


    Unit Seven: Multiplication and Division

    factor –any of the numbers that are multiplied to find

              a  product 

    product- the answer to a multiplication problem 

    square product- the number resulting from multiplying

              a number times that number again

              4, 9, 16, 25, 36…. 

    parentheses- the way to tell which part of a multi-step  algorithm should

         be completed first

    Unit Eight: Fractions

    whole- one complete number or figure, represented

              by the number 1

     denominator- the number below the line in a fraction,

              representing the number of parts you must have to

              make one whole 

    numerator- the number above the line in a fraction

              representing the number of parts you have 

    equivalent fractions- two or more fractions broken into

              different size pieces (having different denominators) that

             represent equal portions of a whole 

    mixed number- a number that combines a whole number and a fraction like

     1 ½

    Unit Nine: Multiplication and Division

    algorithm- a method of solving a problem

    lattice multiplication- a method for solving a multiplication problem using a lattice diagram;

    positive number- a number greater than zero

    negative number- a number less than zero

    degrees Fahrenheit- unit of temperature measurement used in the

        U.S. customary system

    degrees Celsius- unit of temperature measurement used in the metric


    Unit Ten: Measurement and Data

    volume- the amount of space inside a 3-d object, usually measured

        in cubic units

    cubic centimeter- unit of volume measurement; a cube measuring

        1 cm X 1 cm X 1 cm

    weight- measurement of how heavy something is

    capacity- the amount a container or scale can hold

    precision- the accuracy to which something can measure

    mean- an average number in a set of data; the mean is found by adding all

        of the data values and then dividing by the number of numbers in the

        set of data

    median- the middle umber in a set of data when the numbers are put in

        order from smallest to largest or largest to smallest

    mode- the number or value that occurs most often in a set of data

    coordinate- the location of a point on a grid, usually given in ordered pairs

    Unit Eleven: Probability

    probability- a number between 0 and 1 that is used to tell the chance 

        of something happening

    event- something that happens; tossing heads with a coin and rolling 3 

        with a die are events

    random draw- picking out something blindly without looking or in any way

        intentionally making a choice

    chance- the possibility that something will occur

    certain- absolutely sure to occur

    impossible- absolutely sure NOT to occur

    percent- an amount out of 100; 100% means all; 50% means half

    equally likely- having the same chance of happening
    125       100       100