Grade 8 Mathematics

SOL 8.1

exponents / Represents repeated multiplication of the number.

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order of operations / Defines the order in which operations are performed to simplify an expression.
expression / A word used to designate any symbolic mathematical phrase that may contain numbers and/or variables.
Expressions do not contain an equal sign
Base / The number that is multiplied in a power.
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scientific notation / A method used to write very large and very small numbers using the product of a number that is at least one but less than ten and a power of ten.

SOL 8.2

counting number / {1, 2, 3, 4, . . .}
natural number / {1, 2, 3, 4, . . .}
irrational number / A number that cannot be expressed as an integer or the quotient of integers.
rational number / A number that can be expressed as a fraction in the form a/b where a and b do not equal zero
real number / The set of all rational and irrational numbers
repeating decimal / A decimal whose digits repeat in groups of one or more
subset / Includes real numbers, rational numbers, irrational numbers, integers, whole numbers, and natural numbers.

SOL 8.2 (continued)

terminating decimal / A decimal whose digits end. Every terminating decimal can be written as a fraction with a denominator of 10, 100, 1,000, and so on.
whole number / The set of all the natural numbers and zero: {0, 1, 2, 3, …}
integer / The set of whole numbers and their opposites {…-3, -2, -1, 0, 1, 2, 3, . .}

SOL 8.3

debit / A deduction from an amount of money
deposit / An addition that increases an amount of money
discount / A percentage of the original price. The discount is the original price minus the discount.
interest / The amount of money paid or earned for the use of money
markup / The amount the price of an item is increased above the price the store paid for the item
principal / The amount of money invested or borrowed
ratio / A comparison of two numbers by division

SOL 8.3 (continued)

rate / A ratio of two measurements having different units
rate of change / A rate that describes how one quantity changes in relation to another
scale / The ratio of a given length on a drawing or model to its corresponding length in reality
unit rate / A rate with a denominator of 1

SOL 8.4

replacement value / The number that replaces the variables in an algebraic expression
substitute / Replace one variable in one equation with an expression derived from the other equation

SOL 8.5

perfect square / Rational number whose square root is a whole number
principal square root / A positive square root
radical sign / The symbol used to indicate a nonnegative square root
base / The value used as a factor as many times as given by the exponent
exponent / The value that tells how many times the base is used as a factor

SOL 8.6

complementary angles / Any two angles such that the sum of their measures is 90 degrees
supplementary angles / Any two angles such that the sum of their measures is 180 degrees
vertical angles / The opposite angles formed by two intersecting lines. Angles are congruent
congruent / Having the same measure

SOL 8.7

pyramid / A polyhedron with a base that is a polygon and other faces that are triangles with a common vertex
radius / The distance from the center of a circle to any point on the circle
surface area / The sum of the areas of all the faces of a three-dimensional figure
volume / The number of cubic units needed to fill the space occupied by a solid
cone / A geometric solid whose base is a circle and whose side is a surface composed of line segments connecting points on the base to a fixed point (the vertex) not on the base
cylinder / A solid whose bases are congruent, parallel circles, connected with a curved side
diameter / The distance across a circle through its center

SOL 8.7 (continued)

prism / A polyhedron with two parallel, congruent faces called bases
lateral area of a pyramid / The sum of the areas of the triangular faces.
lateral area of a cone / The area of the surface connecting the base with the vertex and is equal to:
rl
vertex / The point of intersection of 2 or more line segments

SOL 8.8

dilation / A transformation that changes the size of a figure by a scale factor to create a similar figure
reflection / A flip of a geometric figure across a line
rotation / A turn of a geometric figure around a fixed point. The rotation can be made clockwise or counterclockwise.
transformation / A mapping of a geometric figure
translation / A slide of a geometric figure in which all the points on the figure move the same distance in the same direction

SOL 8.10

hypotenuse / The side opposite the right angle in a right triangle
legs / The two sides of a right triangle that form the right angle
Pythagorean Theorem / In a right triangle, the square of the length of the hypotenuse c is equal to the sum of the squares of the lengths of the legs a and b. c2 = a2 + b2
Pythagorean triple / A set of three integers that satisfy the Pythagorean Theorem
right angle / An angle that measure 90 degrees
right triangle / A triangle having one right angle

SOL 8.11

probability / The ration of the desired outcomes to the total number of possible outcomes
theoretical probability / Probability based on known characteristics or facts
experimental probability / An estimated probability based on the relative frequency of positive outcomes occurring during an experiment
simple event / A specific outcome or type of outcome
compound event / An event which consists of tow or more simple events
independent events / Two or more events in which the outcome of one event does not affect the outcome of the other event(s)
dependent events / Two or more events in which the outcome of one event does affect the outcome of the other event(s)

SOL 8.12

histogram / A bar chart representing a frequency distribution; heights of the bars represent observed frequencies
circle graph / A type of statistical graph used to compare parts of a whole. The entire represents the whole.
bar graph / A graphic form using bars to make comparisons of statistics
picture graph / A graphic form using pictures to make comparisons of statistics
line graph / A type of statistical graph using lines to show how values change over a period of time.
frequency distribution / Shows how often an item, a number, or a range of numbers occurs
box-and-whisker plot / A diagram that summarizes data using the median, the upper and lower quartiles, and the extreme values. A box is drawn around the quartile values and whiskers extend from each quartile to the extreme data points.

SOL 8.13

matrix / A rectangular arrangement of numerical data in rows and columns
row / In a matrix, the numbers side by side horizontally form a row
column / In a matrix, numbers stacked on top of each other in a vertical arrangement form a column
element / Each number in a matrix is called an element

SOL 8.14

function / A relation in which there is one and only one second member (range) for each first member (domain)
function table / A table of values in which a unique value is assigned to the second variable (range) for each value of the first variable (domain.)
nonlinear function / A function that does not have a constant rate of change. The graph of a nonlinear function is not a straight line.
quadratic function / A function in the second degree; any function that an be described by an equation of the form y=ax2+bx+c, where a ≠ 0
relation / Any set of ordered pairs

SOL 8.16

input / The independent (x) value of a function
linear equation / An equation in two variables whole graph is a line. (The independent variable is limited to the first power.)
linear function / Function in the first degree whose graph is a line
ordered pair (x,y) / A pair of numbers used to locate a point in the coordinate plane. The ordered pair is written in this form (x-coordinate, y-coordinate.)
output / The value of the dependent variable of a function
x / Variable commonly used for the domain, independent variable, or the input of a function
y / Variable commonly used for the range, dependent variable, or the output of a function

SOL 8.16 (continued)

coordinate plane / Another name for the coordinate system which is formed by the intersection of two number lines that meet at right angles at their zero points

SOL 8.17

percent equation / An equivalent form of the percent proportion in which the percent is written as a decimal. Part = Percent . Base
percent of change / A ratio that compares the change in a quantity to the original amount
percent proportion / Compares part of a quantity to the whole quantity using a percent
proportion / A statement of equality of two ratios

SOL 8.18

domain / The set of input values in a function
range / The set of output values in a function
dependent variable / The variable for the output of a function
independent variable / The variable for the input of a function.