 # Glossary Entries

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 Sale Price The price of a product after the discount has been subtracted from the original price. Sales The amount of money generated when goods are sold. Sample A representative part or a single item from a larger whole or group; a finite part of a statistical population whose properties are studied to gain information about the whole. Sample Space A list of all possible outcomes in a given situation. Example:The sample space for tossing two coins is:(H,H), (H,T), (T,H), (T,T). Sampling Sampling is the process of selecting a small group which would be representative of the entire population; used in taking a survey. Scalar Matrix A scalar matrix has diagonal elements that are all equal while the nondiagonal elements are all 0. The identity matrix is an example. Scale (1) The ratio of the size of an object in a representation (drawing) of the object to the actual size of the object; the ratio of the distance on a map to the actual distance (e.g., the scale on a map is 1 inch:10 miles); (2) an instrument used to measure an object’s mass. Scale Drawing A proportionally correct drawing (enlargement or reduction) of an object or area. You can have a drawing that is one-tenth of the actual size of the object. Usually the scale is given, as on a map 1 inch equals 10 miles. Scalene Triangle A scalene triangle has no congruent sides. Scatter Plot Also known as scattergram or scatter diagram. A two dimensional graph representing a collection of data. For each element being graphed, there are two separate pieces of data. Example: The height and weight of a group of 10 teenagers would result in a scatter plot of 10 separate points on the graph. Scientific Notation A form of writing a number as the product of a power of 10 and a decimal number greater than or equal to 1 and less than 10. Examples: 2,400,000 = 2.4 *106, 240.2 = 2.402 102, 0.0024 = 2.4 x10–3 ) Second A unit to measure time. 1 second = 1/60 of a minute. Sector of a Circle The region of the circle formed by two radii and their intercepted arc. Sequence A set of numbers arranged in a special order or pattern. Set A set is a well-defined collection of items. Shape (See geometric shape) Side A line segment joining two adjacent vertices of a polygon. Similar Figures Figures that have the same shape, but not necessarily the same size. Similar Triangles Triangles that have the same shape but not necessarily the same size; corresponding sides are in proportion and corresponding angles are congruent. Similarity Two shapes R and S are similar if there is a dilation D that takes S to a shape congruent to R. R and S are then similar if they are congruent after one of them is expanded or shrunk. This term is used in Geometry with objects that have the same shape, but not the same size. Also see the definition of "Dilation." Simple Interest The amount obtained by multiplying the principal by the rate by the time; I = prt. Example:Sue invested \$200 at a simple interest rate of 3%. Find the interest she will earn in 3 years. Simply Fractions You simplify fractions when you rename fractions to lowest terms by dividing the numerator and denominator by the greatest common factor of the numerator and denominator. Simulation Simulation is the process of carrying out extensive data collection with a simple, safe, inexpensive, easy-to-duplicate event that has essentially the same characteristics as another event that is of actual interest to an investigator. Example: Suppose you wanted to gather data about the actual order of birth of boys and girls in families with five children. (e.g., BBGBG is one possibility) Rather than wait for five children to be born to a single family, or identifying families that already have five children, one could simulate births by repeatedly tossing a coin five times. Heads vs. tails has about the same chance of happening as a boy vs. a girl being born. Sine Sin(q) is the y- coordinate of the point on the unit circle so that the ray connecting the point with the origin makes an angle of q with the positive x- axis. When q is an angle of a right triangle, then sin(q) is the ratio of the opposite side with the hypotenuse. Single-event Experiment A probability experiment in which only one event can occur each time the experiment is performed. Examples: A number cube is rolled once. A coin is tossed once. Skip Count To count by a given number. Example: Skip count by 2’s: 2, 4, 6, 8, 10... Slide Slide is a transformation that slides a figure a given distance in a given direction. A slide is also called a "translation." Slope Slope is the measure of the steepness or incline of a line drawn on a rectangular-coordinate-system graph. It may also be described as the ratio of vertical change to horizontal change.Example: If point P is (x1,y1) and point Q is (x2,y2) the slope of PQ isdelta y/delta x = y2 -y1 / x2-x1. You may also hear about "rise over run" (rise / run). Slope-Intercept Form The equation of a straight line in the form y = mx + b, where m is the slope and b is the y-coordinate of the point where the line intercepts the y-axis. Social Phenomena Problems in the real world relating mathematics and social concepts or events. Example: Sharing 6 cookies among friends. Solid Figure A three-dimensional geometric figure that has length, width, and height. Solution The value or values that make an equation, inequality, or open sentence true. Solution Set The set of values that make an equation or statement true. Solve To find the answer to an equation or a problem. Sort To separate objects into groups according to properties or characteristics. Spatial Reasoning Drawing inferences or conclusions by using visual images. Sphere A three-dimensional figure with a set of points in space that are equidistant from a fixed point called the center. Square A rectangle with two adjacent sides congruent (all four sides will be congruent). Square (Power) When you multiply a number by itself. Ex: The square of 2 is 2 x 2 or 4. Square (Shape) A four sided polygon in which the length of all sides is equal. Square Number A number that is the result of multiplying an integer by itself. Any square number of dots can be arranged in a square array. Square Root The square roots of n are all the numbers m so that m2 = n. A number (factor) that when multiplied by itself yields the original number. The square roots of 16 are 4 or -4. Standard Deviation Standard deviation is a statistic that measures the dispersion of a sample. Standard Form A number is written in standard form when each digit is in a place value. Example: Six thousand five hundred eighty-three has the standard form of 6,583. Statistics Statistics is the collection, organization, presentation, and analysis of data. Stem-and-Leaf Plot This plot is a way of showing the distribution of a set of data along a vertical axis. The ten’s digits of these data are the stems and the one’s digits are the leaves. For Examples, the plot of 2|3654 would show the data 23, 26, 25, 24. Straight Angle A straight angle has a value of 180º. Two rays in opposite directions from their common endpoint form this angle. Straight Edge A straight edge is a tool used to make a straight line. It can be thought of as a ruler without measurement marks. Strategy A method or system of steps used to solve problems.(See problem solving strategies) Subset A set consisting of elements from a given set (e.g., if B = {1,2,3,4,5,6,7} and A = {1,2,3}, then A is a subset of B, written A 'sideways U with line underneath' B). Substitute To replace variables in a given expression or equation with designated values in order to evaluate the expression. Example:To calculate the area of a circle with a radius of 7 cm to the nearest square centimeter, evaluate A=pi*r*r by substituting an approximate value for pi and 7 for "r". Subtraction An arithmetic process where you take one value away from another. The answer in a subtraction problem is called the "difference.". In the real world, you usually take smaller numbers away from larger numbers. In math you can also take larger numbers away from smaller ones and wind up with values less than zero. Subtraction is the opposite process of addition. Subtraction Fact Number fact with minuends to 18 and single-digit subtrahends. Subtraction Sentence This sentence type is an equation showing the difference of two numbers. Example: 10 - 4 = 6. Subtraction Sign A symbol ( - ) that is read as "minus" or "take away" to represent subtraction. Subtrahend The second value in a subtraction problem. Usually a smaller value is subtracted from a larger value. That smaller value would be called the subtrahend. Sum A sum is the answer in an addition problem. Example: 58 + 4 = 62. 62 is the sum. Summary Statistics A single number representation of the characteristics of a set of data. Usually given by measures of central tendency and measures of dispersion (spread). Supplementary Angles Two angles whose measures sum to 180º. Surface Area The surface area is the sum of the areas of the faces or curved surface of a three-dimensional object. The surface area also includes any unseen base area. Survey A survey is a process of asking either written or verbal questions for acquiring information/data. Symbol A notation used to represent an operation or abstract idea (e.g., +, -, >, <, "infinity", or "pi"). Symmetry A figure has symmetry if it has parts that correspond with each other in terms of size, form, and arrangement. For example, a figure with line (or mirror) symmetry has two halves that match each other perfectly if the figure is folded along its line of symmetry. The property of having the same size and shape across a dividing line or around a point. For example, reflection through a diagonal and a rotation through a right angle about the center are both symmetries of the square. System of Equations A set of equations that may share a common solution or common solution(s). System of Inequalities A set of inequalities that may share a common solution or common solution(s). System of Linear Equations Set of equations of the first degree (e.g., x + y = 7 and x - y = 1 ). A solution of a set of linear equations is a set of numbers a, b, c, . . . so that when the variables are replaced by the numbers all the equations are satisfied. For example, in the equations above, x = 4 and y = 3 is a solution.

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