Math 7 Glossary Terms

Transcription

1 Math 7 Glossary Terms Absolute Value Absolute value is the distance, or number of units, a number is from zero. Distance is always a positive value; therefore, absolute value is always a positive value Acute Angle An angle whose measure is greater than 0 and less than 90 is an acute angle. Additive Identity Property The additive identity property states that when 0 is added to any number, the sum is the number itself. Additive Inverse The additive inverse is the number which, when added to a given number, equals zero. a + 0 = a (a) + (-a) = 0 Adjacent Angles Angles that share a vertex and one side but do not overlap are called adjacent angles. Area Area is the number of square units inside the boundary of a 2-dimensional space, such as a polygon or circle. Associative Property In addition and multiplication, the associative property states that the grouping of the addends or factors does not affect the product or sum. a + (b + c) = (a + b) + c a (b c) = (a b) c

2 Base Any side of a polygon can be designated as the base. The base of a three-dimensional figure is a face that is used to measure or classify the figure. Bias Bias is the result of certain parts of a population being over- or under-represented. base base

3 Circle A circle is the set of points equidistant from a given point called the center. Circumference The distance around the edge or boundary of a circle is called the circumference. circle Coefficient The number that is multiplied by the variable in an algebraic expression is called the coefficient. 5x + 10 coefficient Commission Commission is a fee that is a percentage of the selling price of an item. Commutative Property In addition and multiplication, the commutative property states that the order of the addends or factors does not affect the product or sum. a + b + c = b + a + c a b c = c a b Complement The set of all outcomes in a sample space that do not define a given event is called the complement. Complementary Angles A pair of angles whose measures add up to 90 are called complementary angles. Complex Fraction A complex fraction is a fraction where the numerator, denominator, or both contains a fraction ( ) 3 ( ) 4 Composite Figure A figure consisting of two or more geometric figures is called a composite figure. Compound Event A compound event is an event made up of two or more simple events. Congruent Figures having the same size and shape are congruent. Constant In an algebraic expression, a term that has no variable is called a constant. A constant s value does not change. 5x + 10 constant Coordinate Pair A coordinate pair is a description of a location on a graph or a map. y Coordinate Plane A coordinate plane is a plane formed by the intersection of a horizontal number line called the x-axis and a vertical number line called the y-axis. Cross Products When two equivalent ratios are multiplied diagonally, the resulting cross products will always be equal. If a/b = c/d, then ad = bc. Cross Section A cross section is the plane figure shown after cutting across a solid. 1 2 = 4 8 (1)(8) = (2)(4) 8 = 8 x cross section

4 Data Set Information gathered about a population is called the data set. Decimal A decimal is a number based on 10. The term "decimal number" is used to indicate a number that uses a decimal point followed by digits that show a value between zero and one. Denominator The denominator is the number below the fraction bar that names the amount of parts needed to equal one whole unit. Dependent Events Two events in which the occurrence of one has an effect on the probability of the other are called dependent events. Diameter A segment that passes through the center of a circle or sphere is called the diameter. The diameter's endpoints lie on the edge of the circle or sphere. 3 4 denominator diameter Distributive Property The distributive property states that the product of a number and a sum equals the sum of the individual products of the addends and the number. Dot Plot A dot plot is a type of graph used to show the frequency of each value in a data set. a(b + c) = ab + ac

5 Edge A line segment where two faces of a 3-dimensional figure meet is called an edge. edge Equation An equation is a mathematical sentence that contains an equal sign. Equivalent Numbers or expressions having the same value are equivalent. Event An event is one or more possible outcomes of an experiment. Experimental Probability Experimental probability is the ratio of the number of times an event occurred to the total number of trials performed. Exponent An exponent is the number of times that a number is used as a repeated factor. For example, in the expression 2 3, the exponent is 3, which means that 2 is used as a factor 3 times. The expression is equivalent to Expression An expression is a combination of numbers and/or variables and operation symbols (+,, and ). 3x (2 + 5) x 10

6 Face A flat surface of a 3-dimensional figure is called a face. Factors Numbers that are multiplied together to make a product are called factors. face Formula A formula is a mathematical rule or principle, frequently expressed as an equation. Fraction a A fraction is a number in the form b, where b

7 Greatest Common Factor The greatest of the common factors between two or more numbers is called the greatest common factor, or GCF.

8 Height The length of the perpendicular segment from the base to the opposite vertex or side of a geometric figure is called the height. h

9 Identity Property of Multiplication The identity property of multiplication states that the product of any number and 1 is the number itself. Improper Fraction An improper fraction is a fraction in which the numerator is greater than or equal to the denominator. The value of an improper fraction is greater than or equal to 1. a 1 = a 10 2 Inequality An inequality is a representation of two expressions which are not equal (or may or may not be equal). Inequalities are expressed with the symbols,,, and. Integers Integers are the set of positive whole numbers, their opposites, and 0. Interest Interest is a percentage of the amount paid for a loan or earned for a deposit. Interest is expressed as a rate. {..., -4, -3, -2, -1, 0, 1, 2, 3, 4,...} I = P r t Intersecting Lines Intersecting lines are nonparallel lines in a plane. Inverse Operation The operation that reverses the effect of ("undoes ) another operation is called an inverse operation. Of the four basic operations, addition and subtraction are inverses, and multiplication and division are inverses.

10 Mean The mean is the sum of all the data values in a given data set divided by the total number of values. The mean is commonly called the average. Mean Absolute Deviation The average amount that each data value differs from the mean is called the mean absolute deviation. Measures of Central Tendency Measures of central tendency are statistics used to indicate central values of a data set. The mean, the median, and the mode are the three most commonly used measures of central tendency. Median The middle value in a data set is called the median. If there is an even number of values in a data set, the median is determined by taking the average of the two middle values. Mixed Number A mixed number is a number made up of a whole number and a fraction less than Mode The number that appears most often in a set of data is called the mode.

11 Natural Numbers Natural numbers are the set of counting numbers. Negative Integer An integer that is less than zero is called a negative integer. Net A net is a two-dimensional representation of a 3-dimensional figure. Number Line A number line is a visual representation of numbers arranged in order along a line. {1, 2, 3, 4...} negative integers net Numerator The numerator is the number above the fraction bar that names the amount of parts being counted. 3 4 numerator

12 Obtuse Angle An angle whose measure is greater than 90 and less than 180 is called an obtuse angle. Odds Against Odds against refers to the ratio of unfavorable outcomes to favorable outcomes. Odds in Favor Odds in favor refers to the ratio of favorable outcomes to unfavorable outcomes. Operation An operation is a mathematical process such as addition, subtraction, multiplication, or division. Opposites Two integers that are the same distance from zero in opposite directions are called opposites. Order of Operations Order of operations refers to the specific order in which you should perform operations when evaluating expressions: Ordered Pair An ordered pair is a set of two numbers that tells you how far and in which direction to move along each axis to locate a point on a coordinate plane. An ordered pair is written as (x, y). Origin The point of intersection between the x-axis and y-axis on a coordinate plane is called the origin y (0, 0) x Outcome An outcome is a possible result of an experiment. Outlier An outlier is a value that is much less than or much greater than most of the other values in a data set.

13 Parallel Two lines in a plane which do not intersect are parallel. Parallelogram A parallelogram is a quadrilateral whose opposite sides are parallel to each other. Percent Percent is a ratio of a number to 100 and means "parts per hundred." Percent Error Percent error is a percentage that compares an approximate or estimated value to an exact value. Percent Decrease A percentage subtracted from a given value is called a percent decrease. Percent Increase A percentage added to a given value is called a percent increase. Perpendicular Perpendicular lines intersect in right angles. The symbol means perpendicular. Pi Pi, usually shown as the Greek letter π, is the ratio of a circle's circumference to its diameter. In finding area and circumference, (or ) is commonly used to find the approximate measure. 7 π 3.14 Plane A plane is a flat surface that has no thickness or edges and extends forever in all directions. Point A point is a geometric location in space indicated by a dot on a graph. Polygon A polygon is a closed plane figure made of line segments that intersect only at their endpoints. Population A population is an entire group that is being studied. y x Positive Integer An integer greater than zero is called a positive integer positive integers Principal Principal is the initial amount of money borrowed or deposited. Prism A prism is a polyhedron that has two congruent polygon-shaped bases and other faces that are all parallelograms. Probability Probability refers to a number from 0 to 1 (or 0% to 100%) that indicates the likelihood of a given event occurring. Proportion A proportion is a pair of equivalent ratios. 2 4 = 1 2 Pyramid A pyramid is a solid figure with one base positioned opposite of a single point called the "apex." apex base

14 Radius The radius is a segment from the center to a point on the edge of a circle. radius Range The range is a difference between the greatest and the smallest numbers in a set of data. Rate Rate is the ratio of two quantities with different units. Ratio Ratio is a comparison of two quantities :5 3 to 5 Rational Number A rational number is any number that can be expressed as a ratio. Reciprocal Two numbers are reciprocals if their product is 1. The reciprocal of a real 1 number r is. r Rectangle A rectangle is a quadrilateral with four right angles. Repeating Decimal A decimal that has either a single digit or a block of digits that repeats forever is called a repeating decimal = = 0.45 Right Angle A right angle is an angle whose measure equals 90.

15 Sample A sample is a part of a population. Sample Space The set of all possible outcomes of an experiment is called the sample space. Scale Drawing A scale drawing is a drawing in which each dimension in the drawing is reduced or enlarged by a specific amount (the scale) relative to the corresponding dimension in the original object. Scale Factor The scale factor is the specific amount by which a figure is enlarged or reduced. Set A group of items is called a set. Braces { } are often used to indicate a set. Similar Similar figures have the same shape but not necessarily the same size. Simple Random Sampling A simple random sampling is a set of data created by choosing the members of a sample from the entire population. Simplest Form A fraction in which the numerator and denominator have no factors in common besides 1 is in simplest form. Solution A solution is any number that makes a statement true. Square A square is a quadrilateral that has four congruent sides and four right angles. Supplementary Angles A pair of angles whose measures add up to 180 are called supplementary angles. Surface Area Surface area is the total area of all the surfaces of a solid

16 Theoretical Probability Theoretical probability is the chance or likelihood that a given event will occur. Trapezoid A trapezoid is a quadrilateral with only one pair of parallel sides. Tree Diagram A tree diagram is a visual representation of the possible outcomes of an experiment. Trial A trial is the number of times an experiment is performed. Triangle A triangle is a closed plane figure made of three line segments that intersect only at their endpoints. 1st flip 2nd flip H H T H T T outcomes (H, H) (H, T) (T, H) (T, T)

17 Unique Triangle A unique triangle is a triangle of a specific shape and size whose given conditions cannot produce a differently sized or shaped triangle. Unit Rate Unit rate is a rate in which the second quantity is 1. Unit rate is used to compare quantities such as miles per hour or cost per item.

18 Variability Variability is a number that expresses to what extent data points are spread apart or clustered. Variable A variable is a letter that is used to represent a numerical value. Vertex A vertex is the point of intersection of two lines, rays, or segments that form an angle and the point where three faces of a solid meet in a 3-dimensional figure. 5x = 15 variable Vertical Angles A pair of opposite, nonadjacent angles formed by intersecting lines are called vertical angles. Volume Volume is the amount of space occupied by a 3-dimensional object, expressed in cubic units.

19 Whole Numbers Whole numbers are the set of natural numbers and 0. {0, 1, 2, 3, 4...}

20 x-axis The x-axis is the horizontal axis of a coordinate plane. (x, y) x-coordinate The x-coordinate is the first number in an ordered pair, which shows the distance right or left of the origin.

21 y-axis The y-axis is the vertical axis of a coordinate plane. (x, y) y-coordinate The y-coordinate is the second number in an ordered pair, which shows the distance above or below the origin.

22 Zero Pair A zero pair is a pair of numbers whose sum is zero. Zero Property of Multiplication The zero property of multiplication states that the product of any number and 0 is 0. (+1) + (-1) = 0 a 0 = 0