A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q |R | S | T | U | V | W | Y | Z

A
about Key word used to indicate that an estimate is needed.
Act It Out A problem-solving strategy used to express a problem situation physically.
add by making 10 An addition strategy used to break apart numbers to make ten to help find sums of 11 and more.
add down An addition strategy used to add three or more addends.
add up An addition strategy used to add three or more addends.
addend A number that is added to another number or numbers.
addition A joining operation on two or more numbers that gives a total; the sum.
addition sentence A number sentence that involves addition.
addition story A story that involves a joining action.
addition strategies count on, doubles, doubles +1, doubles -1, sums of 10
algorithm The process used for performing a mathematical operation.
altogether Key word used to indicate addition, a joining action.
analog clock A timepiece having hour and minute hands.
analogy A mathematical expression involving two sets where the relationship between the parts of the first set is the same as the relationship between the parts of the second set.
(e.g., 1 is to 4 as 10 is to 40).
area The number of square units needed to cover a flat surface.
associative (grouping) property Changing the grouping of the addends (or factors) does not change the sum (or product).
attribute Any property or characteristic of an object or number.
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B
bar graph A graph that uses bars of different lengths to show data.
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C
calculator A device used to perform computations.
capacity The amount, usually of liquid, a container can hold.
cardinal number A number that indicates how many there are in a set. Examples: one, two,...
CD ROM A compact disc containing information that can be read by a computer.
cent (¢) The smallest U.S. monetary unit, represented as a coin by the penny; 10¢ = 1 dime; 100¢ = 1 dollar.
centimeter (cm) A metric unit used to measure length; 1 cm = 10 mm.
centimeter ruler A metric ruler marked in centimeter increments.
Choose the Operation A problem-solving strategy that involves deciding which mathematical operation to use depending on the language in a word problem.
circle A closed curve in a plane whose points are all the same distance from a given point called the center.
classify To categorize or sort a set of objects, numbers, or other things according to some common attribute.
closed figure A figure that has no openings.
column In a graph, a vertical arrangement of data.
command A word that tells a computer what to do.
commutative (order) property Changing the order of the addends (or factors) does not change the sum (or product).
compare To determine similarities and differences of objects; to determine whether a number is less than, equal to, or greater than another number.
computer A programmable electronic device that can store, retrieve, and process data.
cone A space or solid figure that has one circular base.
congruent (-) A word or symbol used to indicate equivalency of measure.
congruent figures Figures that have the same size and same shape.
coordinate graph A grid in which a horizontal and a vertical number line are drawn to intersect at zero. The relation between the numbers on these number lines is indicated by points.
corner An angle; two rays with a common endpoint.
count back A subtraction strategy used to find differences by counting back from the whole (number in all) a given number of times indicated by the part taken away.
count up An addition strategy used to find sums by counting up from the greater addend a given number of times that is indicated by the second addend.
counting backwards To name numbers in descending order.
counting number Any of the natural numbers 1, 2, 3, 4, 5, ...
counting on To name numbers in ascending order.
cube A solid figure that has six faces, all of which are congruent squares.
cup (c) A customary unit used to measure capacity;
1 c = 8 fl oz; 2 c = 1 pt; 4 c = 1 qt.
curved surface A surface that is not flat.
cylinder A space figure that has a curved surface and two congruent circular bases.
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D
data Factual information used as a basis for reasoning, discussion, or calculation.
date A statement of time indicating a particular day, month, and (sometimes) year. (e.g., September 19, 1999)
day A unit used to measure time; 1 day = 24 hours;
7 days = 1 week.
decimeter (dm) A metric unit used to measure length; 
1 dm = 10 cm; 1 dm = 100 mm.
degree (°) A unit used to measure temperature on the Celsius (°C) or the Fahrenheit (°F) scale; a unit used to measure angles.
degree Celsius (°C) A unit for measuring temperature.
degree Fahrenheit (°F) A unit for measuring temperature.
difference The answer in subtraction.
digit Any one of ten numerals 0 through 9 used to write a number.
digital clock A clock that displays the time in numerical digits.
dime A coin that represents the value of 10 cents (10¢);
1 dime = 10 pennies; 10 dimes = 1 dollar.
display The window on a calculator that shows the information entered.
divided by (÷) A phrase or symbol used between two numbers or expressions that indicates division.
division As sharing: a given set is partitioned into a specified number of groups to determine how many are in each equal group.
As separating: a given set is partitioned by a specified amount to determine how many equal groups.
division sentence A number sentence that involves division.
dollar ($) A U.S. monetary unit equal in value to 100 cents (100¢), and represented by the one dollar bill (or coin); 1 dollar = 100 pennies; 1 dollar = 20 nickels; 1 dollar = 10 dimes; 1 dollar = 4 quarters.
doubles - 1 fact An addition or subtraction fact in which one of the parts is one less than the other. (e.g., 3 + 2 = 5; 7 - 4 = 3)
doubles + 1 fact An addition or subtraction fact in which one of the parts is one more than the other. (e.g., 3 + 4 = 7; 9 - 4 = 5)
doubles fact An addition or subtraction fact in which the parts are the same. (e.g., 3 + 3 = 6; 8 - 4 = 4)
Draw The second of five problem-solving steps used to solve a problem. In this step all given facts are drawn and labeled.
Draw a Picture A problem-solving strategy that involves modeling by drawing a picture in order to make comparisons or complete computations.
Draw to Compare A problem-solving strategy in which the quantity in each of two sets is modeled by drawing, and then the drawings are compared.
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E
edge The line segment where two faces of a space figure meet.
equal parts Portions that are the same size and the same shape.
equal share An equal part of a whole.
equalize To make groups equal by adding more or taking away objects.
equals (=) A word or symbol (=) used to indicate equivalency.
equivalent sets Sets having the same number of members.
estimate An approximate answer; to find an answer that is close to the exact answer.
even number A number that when modeled makes a pair.
expanded form The written form of a number that shows the place value of each of its digits.
Extra Information A problem-solving strategy that requires deciding between relevant and irrelevant information to solve a problem.
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F
face A flat surface of a space figure surrounded by line segments.
fact A number sentence involving the addition or subtraction of two 1-digit numbers.
fact family A set of related addition and subtraction facts that use the same numbers.
fair trade An exchange of money in which the denominations and amounts of coins may change but the total value remains constant.
Find a Pattern A strategy in which the problem solver must discover the pattern in the problem and then extend it.
flat surface A surface that is not curved.
flip A mirror image of a figure, made by flipping the figure across a line.
Follow Directions A problem-solving strategy used when directions are given to solve a problem.
foot (ft) A customary unit used to measure length; 1 ft = 12 in.; 3 ft = 1 yd; 5280 ft = 1 mi.
FORWARD (FD) A LOGO command used to move the LOGO turtle forward a given number of steps.
fraction A number that names part of a whole (or a part of a set). 1 number of parts considered (numerator) 3 number of parts in all (denominator)
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G
gallon (gal) A customary unit used to measure capacity;
1 gal = 4 qt; 1 gal = 8 pt.
gram (g) A metric unit used to measure mass; 1 g = 1000 mg.
graph A drawing that shows a relationship between certain sets of numbers.
grid A network of perpendicular lines used to locate points.
group addends A way to make adding three or more addends easier by counting on or looking for doubles and sums of 10.
Guess and Test A problem-solving strategy that requires the problem solver to guess a solution, test its correctness, and refine the guess using logical reasoning.
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H
half hour A unit used to measure time; 1 half hour = 30 minutes;
2 half hours = 1 hour.
half inch One half of an inch; 2 half inches = 1 inch.
half past A phrase used to indicate a time of 30 minutes past a given hour. (e.g., half past six = 6:30)
halves Parts of a whole that have been divided into 2 equal parts.
height The perpendicular distance between the bases of a geometric figure. In a triangle, the perpendicular segment from the base to the opposite vertex.
hexagon A polygon with six sides.
Hidden Information A strategy that requires the problem solver to discover a piece of information not directly stated in the problem that is necessary to solve it.
home page The opening screen of a Web site.
hour A unit used to measure time; 1 hour = 60 minutes;
24 hours = 1 day.
how many are left Key phrase used to indicate subtraction; the difference or part in a subtraction sentence.
how many in all Key phrase used to indicate addition; the sum or whole in an addition sentence.
hundred chart A 10-by-10 grid displaying the numbers 1 through 100.
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I
identity property of addition The sum of any number and zero is the number itself.
identity property of multiplication The product of any number and 1 is the number itself.
inch (in.) A customary unit used to measure length; 12 in. = 1 ft.
inch ruler A customary ruler marked in inch increments.
inequality A statement that two mathematical expressions are not equal. It uses an inequality symbol: <, >, or -.
Information From a Table A problem-solving strategy that involves using data provided in a table in order to find the correct solution to a problem.
Interpret a Picture A problem solving-strategy that involves examining information shown in a picture in order to make comparisons or complete computations.
is greater than (>) The term or symbol used to indicate an inequality in which the first amount has a greater value than the second amount. (e.g., 16 is greater than 12; 2 + 3 > 1 + 0)
is less than (<) The term or symbol used to indicate an inequality in which the first amount has a lesser value than the second amount. (e.g., 12 is less than 16, 1 + 0 < 2 + 3)
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J
joining An action that indicates addition.
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K
key A list of words or phrases that explains the symbols used in a table or graph.
keyboard Part of a computer used to input information.
kilogram (kg) A metric unit used to measure mass; 1 kg = 1000 g.
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L
LEFT (LT) A LOGO command used to turn the LOGO turtle 90° counterclockwise.
left over Key words to indicate that a separating or sharing action (division) has not resulted in equal groups.
length The measure of distance between two points.
line A set of points, in order, extending indefinitely in opposite directions.
line of symmetry A line on which a figure can be folded so that the two halves exactly match.
line segment A part of a line that has two endpoints.
Listen The first of five problem-solving steps. In this critical step, a problem is carefully listened to or read. Then imagination is used to visualize the problem situation and create a mental picture.
liter (L) A metric unit used to measure capacity; 1 L = 1000 mL.
Logical Reasoning A problem-solving strategy that involves using clues given in a problem in order to eliminate information until the correct solution is arrived at.
LOGO A computer language that can be used to draw figures.
LOGO turtle A graphic element used to indicate the position of the cursor in a LOGO program.
look for patterns A strategy in which systematic increases and/or decreases in the whole or either part consistently produce the same result.
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M
Make a Table A strategy in which the problem solver organizes his/her information by making a table for it in order to solve a problem.
mass The measure of the amount of matter an object contains. (No distinction is made between weight and mass at this level.)
mathematical expression A symbol or a combination of numbers and symbols that represents a number.
meter (m) A metric unit used to measure length; 1 m = 100 cm; 
1 m = 1000 mm.
meterstick A ruler, measuring 1 meter in length, marked with metric increments.
minus (-) A word or symbol used between two numbers to state that the second number is to be subtracted from the first number.
missing addend An unknown addend in addition. (e.g., 8 + ? = 15)
Missing Information A strategy that requires the problem solver to determine a piece of information not present in the problem that is necessary to solve it.
monitor The part of a computer that contains the screen on which information is displayed.
month A unit used to measure time; 12 months = 1 year.
mouse A small movable manual device that controls movement of the cursor on a computer display.
multiplication A joining operation in which a given set is increased by itself a specified number of times.
multiplication sentence An equation that involves multiplication.
multiplied by (x) A phrase or symbol used between two numbers or expressions to indicate multiplication.
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N
near doubles fact An addition or subtraction fact that is a doubles + 1 fact or a doubles - 1 fact.
nickel A coin that represents the value of 5 cents (5¢); 
1 nickel = 5 pennies; 5 nickels = 1 quarter.
nonunit fraction A fraction whose numerator is greater than 1.
nonstandard unit An uncommon or indefinite quantity used to measure. Example: a hand's width.
number A quantity, the value of which may be represented by a numeral, word, or symbol.
counting numbers {1,2,3,4,5,...}
whole numbers {0,1,2,3,4,...}
number in all The whole in an addition or subtraction sentence.
number line A line consisting of points equally spaced, each of which corresponds to a unique number.
number sentence A mathematical sentence that uses numbers, an operation, a relation symbol (<, =, >), and an answer.
numeral A symbol for a number.
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O
odd number A number that when modeled makes a pair with one left over.
ON/AC key A calculator key that turns the calculator on, and when on, clears the display and the memory.
one half One part of a whole that has been divided into 2 equal parts.
1-more pattern A pattern in which each term increases by 1.
one-to-one correspondence An exact match of one member of a set to one member of another set, and vice versa.
open figure A figure that is not closed.
ordered pair A pair of numbers that is used to locate a point on a graph.
ordering numbers Arranging a set of numbers from greatest to least or least to greatest.
ordinal number A number that indicates order or position. For example: first, second, and so on.
Organized List A strategy that uses a systematic arrangement of information to ensure that every possibility will be considered and that there is no repetition when solving a problem.
outcome The result of a probability experiment.
output The results of a computer program.
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P
pair A group of 2.
parallelogram A quadrilateral that has parallel, congruent opposite sides.
part plus part equals whole An addition strategy in which the addends (numbers being added) are the parts and the sum (number in all) is the whole.
pattern A sequence of shapes and/or numbers, colors, or other attributes that are repeated in a predictable way.
penny A coin that represents the value of 1 cent (1¢); 
5 pennies = 1 nickel; 10 pennies = 1 dime; 
25 pennies = 1 quarter; 100 pennies = 1 dollar.
perimeter The distance around a figure.
perpendicular lines Lines that intersect to form right angles.
pictograph A graph that uses pictures or symbols to represent data.
picture graph A graph that uses pictures to represent data.
pint (pt) A customary unit used to measure capacity; 1 pt = 2 c; 2 pt = 1 qt.
place value The value given to the place or position that a digit has in a number.
plane figure A 2-dimensional figure; a flat shape.
plus (+) A word or symbol used between two numbers to state that they should be added together.
pound (lb) A customary unit used to measure weight; 1 lb = 16 oz.
PRINT A statement in the BASIC computer language that tells the computer what to display on the screen.
probability The chance or likelihood of an event occurring.
product The answer in multiplication.
program A set of commands that tells the computer what to do.
pyramid A space figure whose base is a polygon and whose faces are triangles with a common vertex.
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Q
quart (qt) A customary unit used to measure capacity; 1 qt = 2 pt; 
1 qt = 4 c; 4 qt = 1 gal.
quarter A coin that represents a value of 25 cents (25¢); 
1 quarter = 25 pennies; 4 quarters = 1 dollar.
quotient The answer in division.
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R
rectangle A parallelogram with four square corners.
rectangular prism A space or solid figure whose six faces are rectangles.
regrouping Trading and renaming 10 ones as 1 ten or 1 ten as 10 ones.
related facts Addition or subtraction facts in which the whole and the parts are the same. (e.g., 3 + 4 = 7; 7 - 4 = 3)
related multiplication facts Multiplication facts that use the same numbers. 
(e.g., 3 x 2 = 6; 2 x 3 = 6)
repeated addition A joining operation in which a given set is increased by itself a specified number of times; multiplication.
RIGHT (RT) A LOGO command used to turn the LOGO turtle 90° clockwise.
roll A property of space figures with curved surfaces.
Roman numerals Symbols for numbers used by the Romans.
rounding To approximate a number by replacing it with a number expressed in tens, hundreds, thousands, and so on.
row In a graph, a horizontal arrangement of data.
rule The repeating elements in a pattern. A determined method for performing a mathematical operation (s) and obtaining a result.
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S
scale A tool used to measure weight; the ratio of a pictured measure to the actual measure; numbers along the side or bottom of a graph.
second (s) A unit used to measure time; 60 s = 1 min.
sequence A list of ordered events.
set A collection or group of objects or numbers.
shape The visible makeup of a particular item or groups of items.
side A line segment that forms part of a polygon.
skip counting Counting by increments other than 1.
slide A movement of a figure along a plane in a specific direction and distance; a translation.
sort To categorize or classify a set of objects or numbers according to some common attribute.
space (or solid) figure A three-dimensional figure that has volume.
sphere A closed curved figure whose points are all the same distance from a given point called the center.
square A rectangle with 4 equal sides.
square corner The corner of a figure where two line segments meet to form a right angle.
square unit A unit used to measure area.
stack A property of space figures with flat surfaces.
subtraction As comparing: the comparison of two groups to find how many more or fewer one group has than another.
As finding how many more are needed: a part of the whole, or set, is given and the solution is the number needed to complete the set.
As finding part of a whole: a part within the whole is set aside.
As take away: tells how many are left when part of the group is taken away from the whole.
subtraction sentence A number sentence that involves subtraction.
sum The answer in addition.
sums of 10 An addition strategy that involves the use of facts for 10 to find sums of facts for 11 or more.
symmetrical figure A figure that has two congruent halves.
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T
take away A subtraction strategy in which the whole (number in all) is modeled and part is removed.
tally To make a count by items.
tally mark A slash mark used to represent the number 1; / = 1 and - = 5.
ten-frame A rectangle divided into 10 equal parts, used to illustrate numeration and addition and subtraction concepts.
Think The third of five problem-solving steps. In this step the plan for solving the problem is thought out logically and systematically.
think 10 An addition or a subtraction strategy in which the use of facts for 10 are used to find sums or differences of facts of 11 or more.
trading Exchanging 10 ones for 1 ten or 1 ten for 10 ones.
transformation The movement of a figure from one position to another in the same plane; examples: flips, slides, turns.
triangle A polygon with 3 sides.
turn A movement of a figure around a fixed point; rotation.
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U
unit fraction A fraction with a numerator of 1.
Use a Graph This problem-solving strategy involves interpreting or making a graph to solve a problem.
Use a Map A problem-solving strategy in which a map is used to solve a problem.
Use a Model A problem-solving strategy in which modeling is used to solve the problem.
Use Drawings and Models A problem-solving strategy that combines the Draw a Picture and Use a Model strategies; the problem solver uses drawings or models to help find the solution to a problem.
V
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volume The number of cubic units needed to fill a space figure.
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W
week A unit used to measure time; 1 week = 7 days; 52 weeks = 1 year.
weight The heaviness of an object.
whole minus part equals part A subtraction strategy in which the number in all is the whole, the number being subtracted is one part, and the difference (number left over) is the other part.
whole number Any of the numbers 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,...
width The measure of a horizontal dimension of a space figure.
World Wide Web (WWW) A part of the Internet where millions of documents of information can easily be obtained.
Write a Number Sentence A strategy that requires the problem solver to translate the word problem into a number sentence and then solve the sentence.
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Y
yard (yd) A customary unit used to measure length; 1 yd = 3 ft.
yardstick A ruler, measuring 1 yard in length, marked with customary increments.
year A unit used to measure time; 1 year = 12 months; 
1 year = 52 weeks.
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Z
zero property of multiplication The product of any number and zero is zero.
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