245 math terms

Math Glossary

Use this page when a math word is unfamiliar or when you need a quick reminder. Every definition uses the same student-friendly wording as the blue, underlined terms in the class notes.

A

Absolute value
A number’s distance from zero. Distance cannot be negative, so absolute value is never negative.Units 4, 5
Additive inverses
Two numbers whose sum is zero, such as 6 and −6. Each number undoes the other in addition.Units 4, 5
Algebraic expression
A math phrase made of numbers, variables, and operation symbols, but no equals sign.Units 0, 5
Approximately symmetric
A distribution whose left and right sides have roughly the same shape.Unit 9
Area
The amount of flat surface a shape covers, measured in square units.Units 0, 8
Area scale factor
The multiplier that compares areas of similar figures. It is the square of the linear scale factor.Units 6, 8
Association
A pattern in which two variables tend to change together. Association alone does not prove that one causes the other.Unit 9
Average speed
The total distance traveled divided by the total time used.Unit 6

B

Bar graph
A graph with separated bars used to compare amounts in different categories.Unit 9
Base area
The area of the base face used in a prism’s volume formula.Units 0, 8
Base of a power
The number or variable used as the repeated factor in a power.Unit 5
Benchmark
A familiar value, such as 0, one-half, or 1, used to compare or estimate other values.Unit 0
Bias
A problem in a question or sampling method that unfairly pushes results in one direction.Unit 9
Bimodal
Having two values or categories tied for the greatest frequency.Unit 9
Bin
One number interval used to group data values in a histogram.Unit 9
Box plot
A display of the five-number summary with a box showing the middle half of the data.Unit 9
Break-even point
The point where two costs are equal, or where money earned exactly equals money spent.Unit 10

C

Categorical data
Data that sort observations into names or groups instead of measuring them with numbers.Unit 9
Causation
A relationship in which changing one thing actually produces a change in another.Unit 9
Closed circle
A filled circle on a number line showing that the endpoint is included.Unit 4
Cluster
A region of a graph where many data values are grouped close together.Unit 9
Coefficient
The number multiplying a variable. In 7x, the coefficient is 7.Unit 5
Commission
Money earned as a percent of the amount sold.Unit 7
Common denominator
A denominator shared by two or more fractions.Units 0, 3
Common factor
A whole number that divides each of two or more numbers with no remainder.Units 0, 3
Common multiple
A number that is a multiple of each of two or more given numbers.Units 0, 3
Complement percent
The percent still needed to reach 100%. For example, the complement of 35% is 65%.Unit 7
Composite figure
A figure built from two or more simpler shapes.Unit 8
Composite number
A whole number greater than 1 that has more than two positive factors.Unit 3
Congruent figures
Figures with exactly the same shape and size.Unit 8
Conjecture
A mathematical statement that seems true from examples but still needs an explanation or proof.Unit 3
Consecutive integers
Integers in order with a difference of 1, such as 6, 7, and 8.Unit 5
Constant
A fixed number that does not change.Unit 5
Constant of proportionality
The fixed number that multiplies one quantity to produce the other in a proportional relationship.Unit 6
Constraint
A rule or limit that a possible answer must follow.Units 1, 10
Continuous data
Numerical data found by measuring. These data can include values between whole numbers.Unit 9
Convenience sample
A sample made from whoever is easiest to reach. It may not represent the whole population fairly.Unit 9
Conversion factor
A fraction made from two equal measurements and used to change units, such as 12 inches over 1 foot.Unit 6
Coordinate plane
A horizontal and vertical number line that meet at right angles and locate points with ordered pairs.Units 4, 6
Corresponding angles
Angles in matching positions in two figures.Unit 6
Corresponding sides
Sides in matching positions in two figures.Unit 6
Cross multiplication
A method that multiplies diagonally across two fractions or a proportion to form two products.Units 3, 6
Cubic unit
The amount of space inside a cube whose length, width, and height are each 1 unit.Units 0, 8

D

Data set
A collection of values or categories gathered for study.Units 9, 10
Decimal
A number written with a decimal point to show whole-number places and parts smaller than one.Units 0, 2, 7
Decimal point
The dot that separates whole-number places from tenths, hundredths, and smaller places.Units 0, 2
Decimal quotient
A division answer written with decimal places.Unit 2
Decrease multiplier
The decimal factor 1 − r used to apply a percent decrease when r is the decimal rate.Unit 7
Denominator
The bottom number in a fraction. It tells how many equal parts make one whole.Units 0, 3
Dependency chain
A plan showing which results must be found before later steps can begin.Unit 1
Dimensional analysis
A unit-conversion method that multiplies by conversion factors so unwanted units cancel.Unit 6
Discount
An amount taken away from an original price.Unit 7
Discrete data
Numerical data found by counting separate values, such as the number of books.Unit 9
Distribution
The overall shape made by data values, including their center, spread, clusters, gaps, and unusual values.Unit 9
Distributive property
A property that multiplies the factor outside parentheses by every term inside.Unit 5
Dividend
The number being divided in a division problem.Units 0, 2
Divisibility rule
A quick test for deciding whether one whole number divides another with no remainder.Unit 3
Divisible
A number is divisible by another number when the quotient is a whole number with no remainder.Unit 3
Divisor
The number that the dividend is divided by.Units 0, 2

E

Edge
A line segment forming a boundary. On a solid, an edge is where two faces meet.Unit 8
Egyptian fraction
A sum of different unit fractions.Unit 3
Endpoint
The boundary value where a number-line graph or ray begins or ends.Unit 4
Equal measurement
Another name for measurement division: finding how many groups of a given size fit into a total.Unit 2
Equal sharing
Dividing a total equally to find how much belongs in each group.Unit 2
Equation
A mathematical statement saying that two expressions have the same value.Units 0, 5, 6
Equivalent equations
Equations that have exactly the same solution set.Unit 5
Equivalent expressions
Expressions that have the same value for every allowed value of their variables.Unit 5
Equivalent fractions
Fractions that look different but name the same amount.Units 0, 3
Equivalent ratios
Ratios that look different but describe the same comparison.Unit 6
Estimate
A close, reasonable answer used when an exact answer is not needed or to check whether an exact answer makes sense.Units 0, 2
Euler’s relationship
For many solid figures, vertices minus edges plus faces equals 2.Unit 8
Evaluate
To find the numerical value of an expression.Units 0, 5
Expanded form
A way to write a number as the sum of the value of each nonzero digit.Unit 0
Experiment
A study in which researchers assign a treatment and observe what happens.Unit 9
Exponent
The small raised number in a power that tells how many times the base is used as a factor.Unit 5
Expression
A mathematical phrase made of numbers, symbols, or variables without an equals sign.Units 0, 5

F

Face
A flat polygon-shaped surface of a three-dimensional figure.Unit 8
Factor
A number or expression multiplied by another. A whole-number factor also divides a product with no remainder.Units 0, 3, 5
Factor pair
Two whole numbers whose product is a given number.Units 0, 3
Factoring
Rewriting a sum or difference as a multiplication expression.Unit 5
Five-number summary
The minimum, lower quartile, median, upper quartile, and maximum of a data set.Unit 9
Fraction
A number that tells how many equal-sized parts are being counted.Units 0, 3, 6, 7
Frequency
The number of times a value or category appears in a data set.Units 9, 10
Frequency table
A table that lists values or categories and how often each one appears.Unit 9

G

Gap
An interval in or near a data display that contains no observations.Unit 9
Geometric base
The side or face chosen to use with a perpendicular height in an area or volume formula.Unit 8
Greatest common factor (GCF)
The largest positive factor shared by all the given numbers.Units 0, 3
Grouping symbols
Symbols such as parentheses, brackets, and fraction bars that show which parts belong together.Units 0, 5

H

Hidden question
A smaller question that must be answered before the final question can be solved.Unit 1
Histogram
A graph with touching bars that shows numerical data grouped into intervals.Unit 9

I

Identity equation
An equation that is true for every allowed value of its variable.Unit 5
Improper fraction
A fraction whose numerator is at least as large as its denominator.Units 0, 3
Increase multiplier
The decimal factor 1 + r used to apply a percent increase when r is the decimal rate.Unit 7
Inequality
A mathematical statement that compares values using symbols such as <, >, ≤, or ≥.Unit 4
Infinitely many solutions
An equation has infinitely many solutions when there is no end to the different values that make it true. In an identity equation, every allowed value is a solution.Unit 5
Integer
A number in the set ..., −3, −2, −1, 0, 1, 2, 3, ... . Integers include zero, the positive counting numbers, and their opposites.Units 4, 5
Intermediate quantity
An answer from one step that is needed to complete a later step.Units 0, 1
Interquartile range (IQR)
The distance from the lower quartile to the upper quartile, found by subtracting Q1 from Q3.Unit 9
Interval
A span of numbers between stated lower and upper boundaries.Units 9, 10
Inverse operations
Operations that undo each other, such as addition and subtraction or multiplication and division.Units 0, 1, 5

K

KNOWS
The course organizer for recording what we Know, what we Need, the Organization or Operations, the Work, and the Solution.Units 0, 1

L

Ladder method
A method that repeatedly divides numbers by shared prime factors to help find a GCF or LCM.Unit 3
Lateral face
A side face of a prism or pyramid that is not a base.Unit 8
Least common denominator
The smallest positive denominator that two or more fractions can share.Units 0, 3
Least common multiple (LCM)
The smallest positive multiple shared by all the given numbers.Unit 3
Like denominators
Denominators that are the same.Unit 3
Like terms
Terms with exactly the same variables raised to the same powers.Unit 5
Line plot
A number-line display that places a mark above each data value.Unit 9
Linear scale factor
The multiplier applied to every matching length in a scaled figure.Units 6, 8
Linked ratios
Ratios that share a quantity and can be joined after the shared ratio parts are made equal.Unit 6
Long division
A written division method that repeats divide, multiply, subtract, and bring down.Units 0, 2
Lower quartile (Q1)
The middle value of the lower half of an ordered data set.Unit 9

M

Markup
An amount added to a cost to set a higher selling price.Unit 7
Mathematical model
A diagram, table, expression, or equation that shows the important relationships in a situation.Unit 1
Mean
The total of the data values shared equally among the number of values.Unit 9
Mean absolute deviation (MAD)
The average distance of the data values from their mean.Unit 9
Measure of center
A number, such as the mean or median, that describes a typical middle of a data set.Unit 9
Measurement conversion
Renaming the same amount using a different unit.Unit 0
Measurement division
Division used to find how many groups of a given size fit into a total.Unit 2
Median
The middle value after the data are placed in order. With two middle values, use their mean.Unit 9
Mixed number
A number that combines a whole number and a proper fraction.Units 0, 3
Modal interval
The interval in a grouped data display that has the greatest frequency.Unit 9
Mode
The value or category that appears most often in a data set.Unit 9
Multiple
The product of a given number and a whole number.Unit 3
Multiplier
A number used to multiply a quantity. In percent problems, it can combine the starting amount and the change into one step.Units 2, 7

N

Negative number
A number less than zero, located to the left of zero on a number line.Unit 4
Net
A flat arrangement of all a solid’s faces that can fold to make the solid.Unit 8
No solution
A result showing that no value can make an equation true.Unit 5
Nonresponse
A sampling problem that occurs when selected people do not answer and their missing answers may affect the results.Unit 9
Number line
A straight line whose points represent numbers in order.Unit 4
Numerator
The top number in a fraction. It tells how many equal parts are being counted.Units 0, 3
Numerical data
Data made from counts or measurements written as numbers.Unit 9

O

Observation
One recorded person, object, trial, or data value in a study.Unit 9
Observational study
A study that records what happens without telling people which treatment to receive.Unit 9
Open circle
An unfilled circle on a number line showing that the endpoint is not included.Unit 4
Opposite numbers
Numbers the same distance from zero but on different sides of zero.Units 4, 5
Optimization
Finding the greatest, smallest, or otherwise best result that follows all the constraints.Unit 10
Order of operations
The agreed order for completing calculations in an expression so everyone gets the same value.Units 0, 5
Ordered pair
Two numbers or values written in a particular order. On a coordinate plane, (x, y) gives a point’s horizontal and vertical location.Units 0, 4
Organized list
A list that checks possibilities in a clear order so none are skipped or repeated.Unit 1
Origin
The point (0, 0) where the x-axis and y-axis meet.Units 4, 6
Original amount
The starting amount before a percent increase or decrease.Unit 7
Outlier
A data value unusually far from most of the other values.Unit 9

P

Parallelogram
A quadrilateral with both pairs of opposite sides parallel.Unit 8
Part-to-part ratio
A ratio comparing one group with another group.Unit 6
Part-to-whole ratio
A ratio comparing one group with the total.Unit 6
Partial dividend
The place-value amount currently being divided during long division.Units 0, 2
Partial product
One smaller product found before all the products are added to get the final answer.Units 0, 2
Peak
A value or region of a data display with especially high frequency.Unit 9
Percent
A ratio that compares a quantity with 100.Unit 7
Percent change
The amount of change divided by the original amount, written as a percent.Unit 7
Percent decrease
How much an amount shrank compared with its original amount, written as a percent.Unit 7
Percent increase
How much an amount grew compared with its original amount, written as a percent.Unit 7
Percent rate
The percent in a percent problem, usually rewritten as a decimal or fraction before calculating.Unit 7
Perimeter
The total distance around the outside of a flat figure.Unit 8
Perpendicular height
The shortest distance from a base to the opposite side, vertex, or base, measured at a right angle.Unit 8
Place value
The value a digit has because of its position in a number.Units 0, 2
Polygon
A closed, flat figure made only from straight line segments.Unit 8
Polyhedron
A solid figure whose faces are flat polygons.Unit 8
Population
The entire group that a statistical study wants to understand.Unit 9
Positive number
A number greater than zero, located to the right of zero on a number line.Unit 4
Power
The complete expression made from a base and an exponent.Unit 5
Power of ten
A number such as 1, 10, 100, or 1,000 made by repeatedly multiplying by 10.Units 0, 2
Prime factorization
A way to write a composite number as a product containing only prime numbers.Unit 3
Prime number
A whole number greater than 1 with exactly two positive factors: 1 and itself.Unit 3
Prism
A solid with two matching parallel bases joined by side faces.Units 0, 8
Product
The answer to a multiplication problem.Units 0, 2, 3, 5
Proportion
An equation stating that two ratios are equal.Unit 6
Proportional relationship
A relationship in which two quantities always have the same multiplying rate.Unit 6
Pyramid
A solid with one polygon base and triangular faces that meet at one vertex.Unit 8

Q

Quadrant
One of the four regions made by the axes in a coordinate plane.Unit 4
Quadrilateral
A polygon with four sides.Unit 8
Quartile
A dividing point that separates ordered data into four equal-position groups.Unit 9
Quotient
The answer to a division problem.Units 0, 2

R

Random sample
A sample chosen so members of the population have a fair chance of being selected.Unit 9
Range
The difference between the largest and smallest values in a data set.Unit 9
Rate
A ratio comparing quantities measured in different units, such as miles and hours.Units 2, 6
Ratio
An ordered comparison of quantities using division.Unit 6
Ratio part
One equal-size share represented by one unit in a ratio.Unit 6
Ratio table
A table that organizes pairs of equivalent ratios.Unit 6
Rational number
A number that can be written as a fraction of two integers with a denominator that is not zero.Unit 4
Ray
A part of a line that starts at an endpoint and continues forever in one direction.Unit 4
Reciprocal
The reciprocal of a nonzero fraction is found by switching its numerator and denominator. A nonzero whole number n has reciprocal 1/n.Units 0, 3, 6
Reciprocal rate
A rate made by switching the compared quantities, such as miles per hour and hours per mile.Unit 6
Rectangular prism
A box-shaped solid with six rectangular faces.Units 0, 8
Reflection
A transformation that flips a point or shape across a line while keeping the same distance from that line.Unit 4
Relative frequency
A category’s frequency divided by the total number of observations.Unit 10
Remainder
The amount left after making as many equal groups as possible.Units 0, 1, 2
Remaining percent
The percent left after another percent is removed.Unit 7
Repeating decimal
A decimal that continues forever with the same digit or group of digits repeating.Unit 2
Representative sample
A sample that resembles the population in the important ways being studied.Unit 9
Rounding
Replacing a number with a nearby number that is easier to use while keeping about the same value.Units 0, 2

S

Sales tax
A percent of a purchase price added to the bill.Unit 7
Sample
The smaller group actually observed in a statistical study.Unit 9
Sampling variability
The natural differences that occur because different random samples contain different people or items.Unit 9
Scale drawing
A drawing that uses one scale factor to represent a larger or smaller object.Unit 6
Scale factor
The number every matching length or quantity is multiplied by to make a scaled copy.Units 6, 8, 10
Scaled model
A smaller or larger copy whose matching lengths all use the same scale factor.Unit 10
Scaling
Changing a quantity or figure by multiplying or dividing every matching amount by the same factor.Units 2, 6, 8
Similar figures
Figures with the same shape, matching angles, and proportional matching side lengths.Unit 6
Simplest form
A fraction form in which the numerator and denominator have no common factor greater than 1.Units 0, 3
Skewed left
A distribution whose longer, thinner tail points toward smaller values.Unit 9
Skewed right
A distribution whose longer, thinner tail points toward larger values.Unit 9
Slant height
The distance measured along a sloping face of a pyramid or cone, not straight up through the solid.Unit 8
Solid figure
A three-dimensional figure with length, width, and height that takes up space.Units 0, 8
Solution of an equation
A value that makes an equation true when it replaces the variable.Unit 5
Solution set
All values that make an equation or inequality true.Units 4, 5
Spread
How far apart the values in a data set are.Unit 9
Square unit
A square with side length 1 used to measure area.Units 0, 8
Standard algorithm
An agreed-upon step-by-step method for completing a calculation.Units 0, 2
Standard form
Writing a number in the usual way with digits instead of words or expanded addition.Unit 0
Statistic
A number calculated from data to summarize or describe the data set.Units 9, 10
Statistical question
A question that expects different data values instead of one fixed answer.Unit 9
Substitute
To replace a variable with the number it represents.Units 0, 5
Successive percent changes
Two or more percent changes applied one after another, with each change using the newest amount.Unit 7
Surface area
The total area of all exposed outer faces of a solid.Unit 8

T

Tail
The thinner end of a distribution where a few values stretch away from the center.Unit 9
Tally mark
A short mark used to count. Every fifth tally crosses the previous four to make groups of five.Unit 9
Tape diagram
A model that uses labeled bars to show how amounts are joined, compared, or split.Units 1, 6
Term
One number, variable, or product separated from other parts of an expression by addition or subtraction.Unit 5
Terminating decimal
A decimal that ends because the division eventually has a remainder of zero.Unit 2
Tip
Extra money, often found as a percent of a bill, given for service.Unit 7
Trapezoid
A quadrilateral with at least one pair of parallel sides.Unit 8
Treatment
A condition or action assigned to a group in an experiment.Unit 9
Trial quotient digit
A possible quotient digit tested to see whether its product fits in the current partial dividend.Unit 2

U

Unit cube
A cube whose length, width, and height are each 1 unit.Units 0, 8
Unit fraction
A positive fraction with a numerator of 1.Units 0, 3
Unit rate
A rate that tells the amount for exactly 1 unit of the other quantity.Units 2, 6
Unlike denominators
Denominators that are different.Units 0, 3
Upper quartile (Q3)
The middle value of the upper half of an ordered data set.Unit 9

V

Variability
The amount of difference among the values in a data set.Unit 9
Variable (algebra)
A letter or symbol that stands for a number that may change or is not yet known.Units 0, 5
Variable (statistics)
The characteristic recorded for each person, object, or trial in a study.Unit 9
Vertex
A corner point where edges or sides meet. Vertices is the plural of vertex.Unit 8
Volume
The amount of three-dimensional space inside a solid, measured in cubic units.Units 0, 8
Volume scale factor
The multiplier that compares volumes of similar solids. It is the cube of the linear scale factor.Units 6, 8

W

Weighted mean
A mean in which some values count more times or have more importance than others.Unit 9
Whisker
A line on a box plot stretching from the box to an end value.Unit 9
Whole number
A number in the set 0, 1, 2, 3, ... . Whole numbers include zero and the counting numbers.Units 0, 3, 4
Work rate
The part of a job completed in one unit of time.Unit 6
Working backward
A strategy that starts with a known final result and undoes the changes in reverse order.Unit 1

X

x-axis
The horizontal number line in a coordinate plane.Units 4, 6
x-coordinate
The first number in an ordered pair. It tells the horizontal position.Unit 4

Y

y-axis
The vertical number line in a coordinate plane.Units 4, 6
y-coordinate
The second number in an ordered pair. It tells the vertical position.Unit 4