Math Dictionary- Math terms for the year!!

Acute Angle – An angle measuring more than 0 and less than 90 degrees. Adjacent – Next to. Angle – The figure formed when two rays meet at a common endpoint called a vertex. Area – Surface space that is measured in square units. Associative Property of Addition – The Property that states no matter how the numbers, or addends, are grouped, the answer will always be the same. Ex. (4+3)+2 = 4+(3+2) Associative Property of Multiplication - The Property that states no matter how the numbers, or factors, are grouped, the answer will always be the same. Ex. (2x3)x4 = 2x(3x4) Attributes - Characteristics of an object such as its size, shape, or color. Billions - 1,000,000,000; a thousand millions. Capacity – The amount a container can hold. Celsius – The metric scale for measuring temperature. Scientist and people in most countries use thermometers labeled in this scale. Centi- - A prefix meaning one hundredth. Circle – A set of points forming a closed, curved figure in a plane that has no sides. All points in the set are the same distance from one point, called the center. Combinations in Probability – Changes in the order of objects where order is not significant. Common Factor – A number that is a factor of two or more numbers. Commutative Property of Addition – The property that states numbers, or addends, may be added together in any order, and that it will not change the sum. Ex. 2+3 = 3+2 Commutative Property of Multiplication – The property that states numbers, or factors, may be multiplied in any order, and that it will not change the product. Ex. 2x4 = 4x2 Composite Number – A positive whole number with more than two factors. Cone – A geometric figure with one circular base, one curved surface, and one vertex. Congruent – Having the same size and shape. Coordinate – A number pair that locates a point in a plane. Coordinate System – A system used to plot or locate coordinates on a graph. Cube – A geometric figure with six square faces all equal in size. At each vertex, all sides meet at right angles. Cup – A customary unit for measuring capacity. It is equal to the following: 8 fluid ounces, ½ of a pint, ¼ of a quart. It takes 16 of these to make a gallon. Customary Measurement – A measuring system used mainly in the United States. Cylinder – A geometric figure that has both a circular base and a circular top. It also has one curved surface. Decagon – A polygon with ten sides. Deci- - A prefix meaning one tenth. Decimal – A fraction shown in tenths, hundredths, and so on using a decimal point. Decimal Expansion – How a number is written out in full, with a decimal point and digits after the point, which may go on forever. Often it is quicker to write a number as a fraction. Decimal Point – A point between a whole number and a decimal fraction. Decompose – Taking numbers apart. Degrees – A unit for measuring angles or temperature. Deka- - A prefix meaning ten. Denominator – The part of a fraction, below the line of the fraction, that stands for the number of equal parts of a whole or group is divided into. Difference – The amount that remains after one number has been subtracted from another. Divisible – Can be divided without a remainder. Dozen – A group or set of 12. Edge – The line segment where two faces of a geometric figure meet. Elapsed Time – The amount of time that has passed between one event and another. Equal – Two amounts that have the same value. Equation – A statement that two amounts have equal value or measure. Equivalent – Having the same value. Estimate – To make an approximate or rough calculation, often based on rounding. Even Number – Any number that can be evenly divided by 2. These are the numbers that have 0, 2, 4, 6, or 8 in the ones place value. Expanded Form – A way of writing numbers to show place value, or the value of each digit. Expression – One or more numbers, unknowns, and/or operation symbols. These do not contain equal signs, greater than or less than signs. Face – The flat surface of a geometric figure. Fact Family – A group of related facts based on one fact. Factor – Any number that is multiplied to form a product. Fahrenheit – The customary scale for measuring temperature. Most people in the United States use thermometers labeled in this scale. Favorable Combinations – The events that are desired in a probability experiment. Feet – The plural of foot, meaning more than one foot. A customary unit for measuring length and distance. It is equal to both 12 inches and it takes 3 of these to make a yard. It is about the length of a sheet of notebook paper. Fluid Ounce – A customary unit for measuring capacity. It is equal to 1/8 of a cup. Formula – An equation that states a rule or a fact. Fraction – A number that stands for part of a whole or part of a group. Gallon – A customary unit for measuring capacity. It is equal to the following: 128 fluid ounces, 16 cups, 8 pints, and 4 quarts. Gram – A basic metric unit for measuring weight. Graph - A drawing or picture that shows data in an organized way. Greater Than – One number has a larger value than another number. Greatest Common Factor - The largest single factor for two or more numbers. Hecto- - A prefix meaning one hundred. Height – The measurement from top to bottom. Heptagon – A polygon with seven sides. Hexagon – A polygon with six sides. Horizontal – Parallel to the horizon, going east to west, or left to right. Hour - A unit of time that is equal to 60 minutes. Hundred Billions – 100,000,000,000; one hundred groups of one billion. Hundred Millions – 100,000,000; one hundred groups of one million. Hundredths – One part out of 100 equal parts. Identity Property of Addition – When zero is added to a number, the sum is the number itself. Identity Property of Multiplication – When one is multiplied by a number, the product is the number itself. Improper Fraction – A fraction with a numerator that is larger than or equal to its denominator. Inch – A customary unit for measuring length and distance. It takes 12 of these to equal one foot, and 36 of these to equal one yard. It is about the length of a small paper clip. Intersecting Lines – Lines that cross over one another. Inverse Operation – Opposite, reverse operations. Addition and subtraction are opposites, and multiplication and division are opposites. Kilo- - A prefix meaning one thousand. Least Common Multiple – The smallest multiple that two or more numbers have in common. Length – The distance along something from end to end, or the time something lasts from beginning to end. Less Than – One number has a smaller value than another number. Line – A set of points that continue without end in both directions. Line of Symmetry – A line that divides a figure into two halves that are exactly alike. Line Segment – Part of a line that contains the set of points between and including the two endpoints. Liter – A basic metric unit for measuring liquid. Mass – Quantity of matter in an object. Mean – Equal to the sum of values in a set divided by the number in the set. It is also known as the average. Median – The middle value, after ranking the values from least to greatest, of a number in a set. If there is an even number of values in the set, take the mean of the middle two numbers. Meter – A basic metric unit for measuring length and distance. It is about the width of a door. Metric Measurement – A measuring system based on the decimal system and multiples of 10. This is the measurement system used in most of the world. Mile – A customary unit for measuring length and distance. It is equal to 5,280 feet. It is used to measure long distances, such as the distance between two towns. Milli- - A prefix meaning one thousandth. Millions – 1,000,000; equal to one thousand groups of one thousand. Minute - A unit of time that is equal to 60 seconds. Mixed Number – A value that combines a whole number and a fractional amount. Mode – In a set, the value occurring most often. Multiple – Numbers that are in that number’s times table, and divisible by that number with no remainder. Nonagon – A polygon with nine sides. Number Line – A line used to show numbers in order from least to greatest. Number Sentence – An equation that is formed with numbers and mathematical symbols. Numerator – The part of a fraction, above the line of a fraction, that stands for how many parts of a whole or group are included in the fraction. Obtuse Angle – An angle measuring more than 90 and less than 180 degrees. Octagon – A polygon with eight sides. Odd Number – A number that cannot be evenly divided by 2. These are numbers that have 1, 3, 5, 7, or 9 in the ones place value. Operation – A mathematical process such as addition, subtraction, multiplication, and division. Ordered Pair – Two numbers that identify a point on a grid. Ounce – A customary unit for measuring weight. It takes 16 of these to equal a pound. Parallel – Lines in the same plane that are the same distance apart and do not intersect. Parallelogram – A quadrilateral with two pairs of congruent, parallel sides. Pattern – Things that happen over and over again. A repeated design or recurring sequence. Pentagon – A polygon with five sides. Perimeter – The distance around a figure. Permutations in Probability – Changes in the order of objects where order is significant. Perpendicular – Intersecting lines that cross to form 90 degree angles. Pint – A customary unit for measuring capacity. It is equal to the following: 16 fluid ounces and 2 cups. It takes 2 of these to equal one quart, and 8 of these to equal one gallon. Place Value – The amount that each digit stands for in a number. Point – A position in space, or a position on a number line. Polygon – Three or more line segments in a plane that form a closed figure. Possible Combinations - The total number of events that can happen in a probability experiment. Pound – A customary unit for measuring weight. It is equal to 16 ounces. Prime Factor – A factor that is also a prime number. Prime Factorization – Breaking down a composite number until all of the factors are prime. Prime Number – A number with only two factors: the number itself and 1. Prism – A solid figure that has two congruent, parallel polygons as its bases. Probability – The chance that a particular outcome will occur, measured as a ratio of the total possible outcomes. Product – The result of multiplying two or more numbers. Proper Fraction – A fraction that is smaller than one whole, and the denominator is larger than the numerator. Proportion – An equation stating that two ratios are equal. Pyramid – A solid figure that has triangles for its sides and a polygon as its base. Quadrilateral – A polygon that has four sides. Quart – A customary unit for measuring capacity. It is equal to the following: 32 fluid ounces, 4 cups, and 2 pints. It takes four of these to equal a gallon. Quotient – The result of dividing one number by another; the solution to a division problem. Range – The difference between the least and greatest values in a set of numbers. Ray – Part of a line that extends an infinite distance from an endpoint at one end. Reasonable – An answer that is neither extreme nor excessive, and make sense. Rectangle – A quadrilateral with four equal angles, and two pairs of equal parallel sides. Rectangular Prism – A geometric figure with six rectangular faces. At each vertex, all sides meet at right angles. Rectangular Pyramid – A geometric figure with 5 faces. Four of the faces are triangles, and one of the faces is a rectangle. Reflection – A mirror image of a figure drawn across a line of symmetry. Remainder – The left over amount after dividing a number. Rhombus – A quadrilateral with all sides equal and congruent. Right Angle – An angle that measures 90 degrees. Rotation – Turning a figure without changing its size or shape. Round - Change a number to a more convenient value. Second - A standard unit of time. It takes 60 of these to equal 1 minute. Simplify – To make a fraction easier to work with by taking out common factors. Solid – A three-dimensional figure having length, width, and height. Sphere – A geometric figure made up of a set of points forming a curved figure. All points in the set are the same distance from the center, and it is similar to a ball. Square – A quadrilateral with all four sides equal and all four angles equal to 90 degrees. Square Pyramid – A solid figure that has 5 faces, 1 face that is square, and 4 faces that are triangles. Straight Angle – An angle that measures 180 degrees. Sum – The total of two or more numbers being added. Temperature – A measure of how hot or cold something is. Ten Billions – 10,000,000,000; equal to ten groups of one billion. Ten Millions – 10,000,000; equal to ten groups of one million. Tenths – One part out of 10 equal parts. Thousandths – One part out of one thousand. Ton – A customary unit for measuring weight. It is equal to 2000 pounds. Translation – A change in position, resulting from a slide with no turn. Trapezoid – A quadrilateral with one pair of parallel sides. Triangle – A three-sided polygon with three angles totaling 180 degrees. Triangular Prism – A solid with 5 faces. 2 of the faces are triangles and 3 of the faces are rectangles. Triangular Pyramid – A solid figure with 4 triangular faces. Trillions – 1,000,000,000,000; a thousand groups of one billion. Vertex – The point of intersection for two sides of a plane figure, three sides of a solid figure, or the endpoints of two rays that form an angle; a corner. The plural of this is vertices. Vertical – At right angles to the horizon, north to south, up and down, top to bottom. Volume – The amount of space an object takes up. It is usually measured in cubic units. Weight – The mass of the object times the force of gravity. Whole Number – The set of numbers that includes zero and all of the natural numbers (1, 2, 3, 4, and so on.) X-Axis – The horizontal number line of a coordinate graph. Yard – A customary unit for measuring length and distance. It is equal to both 36 inches and 3 feet. It is about the width of a door. Y-Axis – The vertical number line of a coordinate graph.

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