Skills available for
West Virginia eighth-grade math standards
IXL's eighth-grade skills will
be aligned to the West Virginia Next Generation Content Standards and Objectives (Common Core) soon!
Until then, you can view a complete list of
are in black
and IXL math skills are in dark green. Hold your
mouse over the name of a skill to view a sample problem.
Click on the name of a skill to practice that skill.
8 Reason quantitatively and use units to solve problems.
8.M.1HS8.RBQ.1 Use units as a way to understand problems and to guide the solution of multi-step problems; choose and interpret units consistently in formulas; choose and interpret the scale and the origin in graphs and data displays.
8 Create equations that describe numbers or relationships
8.M.1HS8.RBQ.5 create equations and inequalities in one variable and use them to solve problems. Include equations arising from linear and quadratic functions and simple rational and exponential functions.
8.M.1HS8.RBQ.6 Create equations in two or more variables to represent relationships between quantities; graph equations on coordinate axes with labels and scales.
8.M.1HS8.LER.2 Explain why the x-coordinates of the points where the graphs of the equations y = f(x) and y = g(x) intersect are the solutions of the equation f(x) = g(x); find the solutions approximately, e.g., using technology to graph the functions, make tables of values, or find successive approximations. Include cases where f(x) and/or g(x) are linear, polynomial, rational, absolute value, exponential, and logarithmic functions.
8.M.1HS8.LER.3 Graph the solutions to a linear inequality in two variables as a half-plane (excluding the boundary in the case of a strict inequality), and graph the solution set to a system of linear inequalities in two variables as the intersection of the corresponding half-planes.
8 Understand the concept of a function and use function notation
8.M.1HS8.LER.4 understand that a function is a rule that assigns to each input exactly one output. The graph of a function is the set of ordered pairs consisting of an input and the corresponding output.
8.M.1HS8.LER.5 Compare properties of two functions each represented in a different way (algebraically, graphically, numerically in tables, or by verbal descriptions).
8.M.1HS8.LER.6 interpret the equation y = mx + b as defining a linear function, whose graph is a straight line; give examples of functions that are not linear.
8.M.1HS8.LER.7 Understand that a function from one set (called the domain) to another set (called the range) assigns to each element of the domain exactly one element of the range. If f is a function and x is an element of its domain, then f(x) denotes the output of f corresponding to the input x. The graph of f is the graph of the equation y = f(x).
8.M.1HS8.LER.10 construct a function to model a linear relationship between two quantities. Determine the rate of change and initial value of the function from a description of a relationship or from two (x, y) values, including reading these from a table or from a graph. Interpret the rate of change and initial value of a linear function in terms of the situation it models, and in terms of its graph or a table of values.
8.M.1HS8.LER.11 describe qualitatively the functional relationship between two quantities by analyzing a graph (e.g., where the function is increasing or decreasing, linear or nonlinear). Sketch a graph that exhibits the qualitative features of a function that has been described verbally.
8 Interpret functions that arise in applications in terms of the context
8.M.1HS8.LER.12 For a function that models a relationship between two quantities, interpret key features of graphs and tables in terms of the quantities, and sketch graphs showing key features given a verbal description of the relationship.
8.M.1HS8.LER.19 Identify the effect on the graph of replacing f(x) by f(x) + k, k f(x), f(kx), and f(x + k) for specific values of k (both positive and negative); find the value of k given the graphs. Experiment with cases and illustrate an explanation of the effects on the graph using technology.
8.M.1HS8.LER.21 Construct linear and exponential functions, including arithmetic and geometric sequences, given a graph, a description of a relationship, or two input-output pairs (include reading these from a table).
8 Understand solving equations as a process of reasoning and explain the reasoning
8.M.1HS8.RWE.1 Explain each step in solving a simple equation as following from the equality of numbers asserted at the previous step, starting from the assumption that the original equation has a solution. Construct a viable argument to justify a solution method.
8.M.1HS8.RWE.3 analyze and solve pairs of simultaneous linear equations.
8.M.1HS8.RWE.3.a understand that solutions to a system of two linear equations in two variables correspond to points of intersection of their graphs, because points of intersection satisfy both equations simultaneously.
8.M.1HS8.RWE.3.b solve systems of two linear equations in two variables algebraically, and estimate solutions by graphing the equations. Solve simple cases by inspection.
8.M.1HS8.RWE.3.c solve real-world and mathematical problems leading to two linear equations in two variables.
8 Solve systems of equations
8.M.1HS8.RWE.4 Prove that, given a system of two equations in two variables, replacing one equation by the sum of that equation and a multiple of the other produces a system with the same solutions.
8.M.1HS8.DST.2 Use statistics appropriate to the shape of the data distribution to compare center (median, mean) and spread (interquartile range, standard deviation) of two or more different data sets.
8.M.1HS8.DST.4 construct and interpret scatter plots for bivariate measurement data to investigate patterns of association between two quantities. Describe patterns such as clustering, outliers, positive or negative association, linear association and nonlinear association.
8.M.1HS8.DST.5 know that straight lines are widely used to model relationships between two quantitative variables. For scatter plots that suggest a linear association, informally fit a straight line and informally assess the model fit by judging the closeness of the data points to the line.
8.M.1HS8.DST.6 use the equation of a linear model to solve problems in the context of bivariate measurement data, interpreting the slope and intercept.
8.M.1HS8.DST.7 understand that patterns of association can also be seen in bivariate categorical data by displaying frequencies and relative frequencies in a two-way table. Construct and interpret a two-way table summarizing data on two categorical variables collected from the same subjects. Use relative frequencies calculated for rows or columns to describe possible association between the two variables.
8 Summarize, represent, and interpret data on two categorical and quantitative variables
8.M.1HS8.DST.8 Summarize categorical data for two categories in two-way frequency tables. Interpret relative frequencies in the context of the data (including joint, marginal, and conditional relative frequencies). Recognize possible associations and trends in the data.
8.M.1HS8.DST.9 Represent data on two quantitative variables on a scatter plot, and describe how the variables are related.
8.M.1HS8.DST.9.a Fit a function to the data; use functions fitted to data to solve problems in the context of the data.
8.M.1HS8.DST.9.b Informally assess the fit of a function by plotting and analyzing residuals.
8.M.1HS8.DST.10 Interpret the slope (rate of change) and the intercept (constant term) of a linear model in the context of the data.
8.M.1HS8.DST.11 Compute (using technology) and interpret the correlation coefficient of a linear fit.
8.M.1HS8.DST.12 Distinguish between correlation and causation.
8.M.1HS8.CPC Congruence, Proof, and Constructions
8 Experiment with transformations in the plane
8.M.1HS8.CPC.1 Know precise definitions of angle, circle, perpendicular line, parallel line, and line segment, based on the undefined notions of point, line, distance along a line, and distance around a circular arc.
8.M.1HS8.CPC.2 Represent transformations in the plane using, e.g., transparencies and geometry software; describe transformations as functions that take points in the plane as inputs and give other points as outputs. Compare transformations that preserve distance and angle to those that do not (e.g., translation versus horizontal stretch).
8.M.1HS8.CPC.5 Given a geometric figure and a rotation, reflection, or translation, draw the transformed figure using, e.g., graph paper, tracing paper, or geometry software. Specify a sequence of transformations that will carry a given figure onto another.
8.M.1HS8.CPC.6 Use geometric descriptions of rigid motions to transform figures and to predict the effect of a given rigid motion on a given figure; given two figures, use the definition of congruence in terms of rigid motions to decide if they are congruent.
8.M.1HS8.CPC.7 Use the definition of congruence in terms of rigid motions to show that two triangles are congruent if and only if corresponding pairs of sides and corresponding pairs of angles are congruent.
8.M.1HS8.CPC.8 Explain how the criteria for triangle congruence (ASA, SAS, and SSS) follow from the definition of congruence in terms of rigid motions.
8 Make geometric constructions
8.M.1HS8.CPC.9 Make formal geometric constructions with a variety of tools and methods (compass and straightedge, string, reflective devices, paper folding, dynamic geometric software, etc.).
8.M.1HS8.CAG Connecting Algebra and Geometry through Coordinates
8 Use coordinates to prove simple geometric theorems algebraically
8.M.1HS8.CAG.1 Use coordinates to prove simple geometric theorems algebraically.
8.M.1HS8.CAG.2 Prove the slope criteria for parallel and perpendicular lines and use them to solve geometric problems (e.g., find the equation of a line parallel or perpendicular to a given line that passes through a given point).