Grade 8  Math
Terms
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 radical
 The indicated root of a quantity.
 terminating decimal
 A decimal number that does not repeat.
 repeating decimal
 A decimal in which a digit or a set of digits repeat infinitely.
 pi
 The ratio of a circle's circumference to its diameter. Approximately equal to 3.14.
 square root

A number that when multiplied by itself produces a given number.
Example:
3 is the square root of 9  perfect square
 A number that is the square of an integer.
 cube root
 The number that must be multiplied by itself and then by itself again to produce a given number.
 rounding
 Approximating the value of a number to a given decimal place.
 place value
 The value given to a place a digit may occupy in a numeral.
 benchmark
 A point of reference from which measurements can be made.
 base

[1]The side or face on which a threedimensional shape stands;
[2]The number of characters a number system contains.  height
 The distance from the base to the top of a figure.
 radius
 A line segment from the center of a circle to any point on its circumference.
 diameter
 A line segment that passes through the center of a circle and divides it in half.
 circumference
 The distance around a circle, calculated by multiplying the diameter by the value pi.
 polygon
 A simple, closed plane figure, having three or more line segments as sides.
 prism
 A solid figure that has two parallel, congruent polygonal facs (called bases).
 cube
 A solid figure with six square faces.
 cylinder
 A solid shape with parallel circular bases.
 similar figures
 Have the same shape but are not necessarily the same size.
 ratio
 A comparison of two numbers.
 proportion
 A statement that two ratios are equal.
 scale drawing
 A proportionally correct drawing of an object or area at actual, enlarged, or reduced size.
 Pythagorean Theorem
 A mathematical idea stating that the sum of the squared lengths of the two shorter sides of a right triangle is equal to the squared length of the hypotenuse.
 right triangle
 A triangle with one right angle.
 hypotenuse
 The side of a right triangle, opposite the right angle.
 legs
 The two sides of a right triangle that form the right angle.
 Pythagorean triple
 A set of three integers that satisfy the Pythagorean Theorem.
 area
 The size of a surface, usually expressed in square units.
 volume
 The space occupied by a solid, measured in cubic units.
 perimeter
 The distance around the outside of a closed figure.
 square
 To multiply a number by itself; shown by the exponent 2.
 irrational numbers
 The set of all numbers that cannot be expressed as finite or repeating decimals.
 transformation
 A mathematical process that changes the shape or position of a geometric figure.
 scale
 The ratio between the actual size of an object and proportional representation.
 scale factor
 The factor by which all the components of an object are multiplied in order to create a proportional enlargement.
 scatter plot
 A twodimensional graph in which the points corresponding to two related factors (for example, smoking and life expectancy) are graphed and observed for correlation.
 trend
 A consistent change over time in the statistical data representing a particular population.
 yintercept
 The point at which a line or curve cuts across the yaxis.
 xintercept
 The point at which a line or curve cuts across the xaxis.
 ordered pair
 Two numbers that tell the xcoordinate and ycoordinate of a point.
 slope

[1]A way of describing the steepness of a line, ramp, hill, and so on;
[2]The ratio of the rise to the run.  measures of central tendancy
 Numbers or pieces of data that can represent the whole set of data.
 mean
 The sum of the numbers in a set of data divided by the number of pieces of data in the data set.
 median
 The middle number in a set of data when the data are arranged in numerical order. If the data has an even number, the median is the mean of the two middle numbers.
 mode
 The number(s) or item(s) that appear most often in a set of data.
 range
 In statistics, the difference between the largest and smallest values in a sample.
 sample
 A finite subset of a population, used for statistical analysis.
 random sample
 A population sample chosen so that each member has the same probabilty of being selected.
 function
 Assigns exactly one output value to each input value.
 solution
 The answer to a mathematical problem. In algebra, a solution usually consists of a value or set of values for a variable.
 variable
 A letter or other symbol that represents a number or set of numbers in an expression or an equation.
 equation
 A mathematical sentence stating that two expressions are equal.
 intercept

[1]The cutting of a line, curve, or surface by another line, curve, or surface;
[2]The point at which a line or curve cuts across a given axis.  commutative property
 The mathematical rule that states that the order in which numbers are added or multiplied has no effect on the sum or product.
 associative property
 A rule that states that the sum or product of a set of numbers is the same, no matter how the numbers are grouped.
 additive inverse
 A number that when added to given number results in a sum of zero.
 multiplicative inverse
 The number for any given number that will yield 1 when the two are multiplied, same as reciprocal.
 nonlinear function
 A function that does not have a constant rate of change. The graph of a nonlinear function is not a straight line.
 linear function
 A function in which the graph of the solutions forms a line.
 corresponding parts
 Parts of congruent or similar figures that match.
 complementary angles
 Two angles are complementary if the sum of their measures is 90°.
 supplementary angles
 Two angles are supplementary if the sum of their measures is 180°.
 coordinate plane
 A plane in which a horizontal number line and vertical number line intersect at their zero points.
 dependent variable
 The variable for the output of a function.
 independent variable
 The variable for the input of a function.
 outlier
 Data that is more than 1.5 times the interquartile range from the upper or lower quartiles.
 biased sample
 A sample drawn in such a way that one or more parts of the population are favored over others.
 function table
 A table organizing the input, rule, and output of a function.
 coefficient
 The numerical factor of a term that contains a variable.
 slopeintercept form
 An equation written in the form y=mx+b, where m is the slope and b is the yintercept.
 parallel lines
 Lines in the same plane that never intersect or cross.
 perpendicular lines
 Two lines that intersect to form right angles.
 line of best fit
 A line that is very close to most of the data points.
 domain
 The set of input values in a function.

nonterminating
decimal  A decimal number that does not end.
 ascending order

Listing numbers from least to greatest.
Example: 1,2,3,4,5...  descending order

Listing numbers from greatest to least.
Example: 10,9,8,7,6,...  extraneous information
 Extra information in a word problem that is not necessary to solve the problem.
 positive correlation
 Graph shows a positive slope.
 negative correlation
 Graph shows a negative slope.
 enlargement
 To make a geometric figure larger
 reduction
 To make a geometric figure smaller
 shrink
 To make a geometric figure smaller
 image
 A figure after dilation.
 preimage
 A figure before dilation.
 similarity
 Having the same qualities.
 trend/correlation
 Relationship between two variables.
 no correlation
 Graph showing no relationship.
 function notation

The way a function is recognized.
Example: f(x)  standard form
 ax+by=c
 intersecting lines
 Lines that cross at a point.
 radical expression
 An expression that has a square root.