Commom Core State Standards for Mathematics | Grade 8
Grade 8 Introduction
In Grade 8, instructional time should focus on three critical areas: (1) formulating and reasoning about expressions and equations,
including modeling an association in bivariate data with a linear equation, and solving linear equations and systems of linear
equations; (2) grasping the concept of a function and using functions to describe quantitative relationships; (3) analyzing two- and
three-dimensional space and figures using distance, angle, similarity, and congruence, and understanding and applying the
Pythagorean Theorem.
Students use linear equations and systems of linear equations to represent, analyze, and solve a variety of problems.
Students recognize equations for proportions (y/x = m or y = mx) as special linear equations (y = mx + b), understanding
that the constant of proportionality (m) is the slope, and the graphs are lines through the origin. They understand that the
slope (m) of a line is a constant rate of change, so that if the input or x-coordinate changes by an amount A, the output or ycoordinate
changes by the amount m·A. Students also use a linear equation to describe the association between two
quantities in bivariate data (such as arm span vs. height for students in a classroom). At this grade, fitting the model, and
assessing its fit to the data are done informally. Interpreting the model in the context of the data requires students to
express a relationship between the two quantities in question and to interpret components of the relationship (such as
slope and y-intercept) in terms of the situation.
Students strategically choose and efficiently implement procedures to solve linear equations in one variable,
understanding that when they use the properties of equality and the concept of logical equivalence, they maintain the
solutions of the original equation. Students solve systems of two linear equations in two variables and relate the systems
to pairs of lines in the plane; these intersect, are parallel, or are the same line. Students use linear equations, systems of
linear equations, linear functions, and their understanding of slope of a line to analyze situations and solve problems.
Grade 8 Overview
The Number System
Know that there are numbers that are not rational, and approximate them by rational numbers.
Expressions and Equations
Work with radicals and integer exponents.
Understand the connections between proportional relationships, lines, and linear equations.
Analyze and solve linear equations and pairs of simultaneous linear equations.
Functions
Define, evaluate, and compare functions.
Use functions to model relationships between quantities.
Geometry
Understand congruence and similarity using physical models, transparencies, or geometry software.
Understand and apply the Pythagorean Theorem.
Solve real-world and mathematical problems involving volume of cylinders, cones and spheres.
Statistics and Probability
Investigate patterns of association in bivariate data.
Mathematical Practices
1. Make sense of problems and persevere in solving them.
2. Reason abstractly and quantitatively.
3. Construct viable arguments and critique the reasoning of others.
4. Model with mathematics.
5. Use appropriate tools strategically.
6. Attend to precision.
7. Look for and make use of structure.
8. Look for and express regularity in repeated reasoning.
Grade 8 The Number System
Standards in this domain:
CCSS.MATH.CONTENT.8.NS.A.1 CCSS.MATH.CONTENT.8.NS.A.2
Know that there are numbers that are not rational, and approximate them by rational numbers.
CCSS.MATH.CONTENT.8.NS.A.1 (HTTP://WWW.CORESTANDARDS.ORG/MATH/CONTENT/8/NS/A/1/)
Know that numbers that are not rational are called irrational. Understand informally that every number has a decimal expansion;
for rational numbers show that the decimal expansion repeats eventually, and convert a decimal expansion which repeats
eventually into a rational number.
CCSS.MATH.CONTENT.8.NS.A.2 (HTTP://WWW.CORESTANDARDS.ORG/MATH/CONTENT/8/NS/A/2/)
Use rational approximations of irrational numbers to compare the size of irrational numbers, locate them approximately on a
number line diagram, and estimate the value of expressions (e.g., π ). For example, by truncating the decimal expansion of √2,
show that √2 is between 1 and 2, then between 1.4 and 1.5, and explain how to continue on to get better approximations.
Grade 8 Expressions & Equations
Standards in this domain:
CCSS.MATH.CONTENT.8.EE.A.1 CCSS.MATH.CONTENT.8.EE.A.2 CCSS.MATH.CONTENT.8.EE.A.3
CCSS.MATH.CONTENT.8.EE.A.4 CCSS.MATH.CONTENT.8.EE.B.5 CCSS.MATH.CONTENT.8.EE.B.6
CCSS.MATH.CONTENT.8.EE.C.7 CCSS.MATH.CONTENT.8.EE.C.8
Expressions and Equations Work with radicals and integer exponents.
CCSS.MATH.CONTENT.8.EE.A.1 (HTTP://WWW.CORESTANDARDS.ORG/MATH/CONTENT/8/EE/A/1/)
Know and apply the properties of integer exponents to generate equivalent numerical expressions. For example, 3 × 3 = 3 =
1/3 = 1/27.
CCSS.MATH.CONTENT.8.EE.A.2 (HTTP://WWW.CORESTANDARDS.ORG/MATH/CONTENT/8/EE/A/2/)
Use square root and cube root symbols to represent solutions to equations of the form x = p and x = p, where p is a positive
rational number. Evaluate square roots of small perfect squares and cube roots of small perfect cubes. Know that √2 is irrational.
CCSS.MATH.CONTENT.8.EE.A.3 (HTTP://WWW.CORESTANDARDS.ORG/MATH/CONTENT/8/EE/A/3/)
Use numbers expressed in the form of a single digit times an integer power of 10 to estimate very large or very small quantities,
and to express how many times as much one is than the other. For example, estimate the population of the United States as 3
times 10 and the population of the world as 7 times 10 , and determine that the world population is more than 20 times larger.
CCSS.MATH.CONTENT.8.EE.A.4 (HTTP://WWW.CORESTANDARDS.ORG/MATH/CONTENT/8/EE/A/4/)
Perform operations with numbers expressed in scientific notation, including problems where both decimal and scientific notation are used. Use scientific notation and choose units of appropriate size for measurements of very large or very small quantities (e.g.,
use millimeters per year for seafloor spreading). Interpret scientific notation that has been generated by technology
Understand the connections between proportional relationships, lines, and linear equations.
CCSS.MATH.CONTENT.8.EE.B.5 (HTTP://WWW.CORESTANDARDS.ORG/MATH/CONTENT/8/EE/B/5/)
Graph proportional relationships, interpreting the unit rate as the slope of the graph. Compare two different proportional
relationships represented in different ways. For example, compare a distance-time graph to a distance-time equation to
determine which of two moving objects has greater speed.
CCSS.MATH.CONTENT.8.EE.B.6 (HTTP://WWW.CORESTANDARDS.ORG/MATH/CONTENT/8/EE/B/6/)
Use similar triangles to explain why the slope m is the same between any two distinct points on a non-vertical line in the
coordinate plane; derive the equation y = mx for a line through the origin and the equation y = mx + b for a line intercepting the
vertical axis at b.
Analyze and solve linear equations and pairs of simultaneous linear equations.
CCSS.MATH.CONTENT.8.EE.C.7 (HTTP://WWW.CORESTANDARDS.ORG/MATH/CONTENT/8/EE/C/7/)
Solve linear equations in one variable.
CCSS.MATH.CONTENT.8.EE.C.7.A (HTTP://WWW.CORESTANDARDS.ORG/MATH/CONTENT/8/EE/C/7/A/)
Give examples of linear equations in one variable with one solution, infinitely many solutions, or no solutions. Show which of
these possibilities is the case by successively transforming the given equation into simpler forms, until an equivalent equation
of the form x = a, a = a, or a = b results (where a and b are different numbers).
CCSS.MATH.CONTENT.8.EE.C.7.B (HTTP://WWW.CORESTANDARDS.ORG/MATH/CONTENT/8/EE/C/7/B/)
Solve linear equations with rational number coefficients, including equations whose solutions require expanding expressions
using the distributive property and collecting like terms.
CCSS.MATH.CONTENT.8.EE.C.8 (HTTP://WWW.CORESTANDARDS.ORG/MATH/CONTENT/8/EE/C/8/)
Analyze and solve pairs of simultaneous linear equations.
CCSS.MATH.CONTENT.8.EE.C.8.A (HTTP://WWW.CORESTANDARDS.ORG/MATH/CONTENT/8/EE/C/8/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.
CCSS.MATH.CONTENT.8.EE.C.8.B (HTTP://WWW.CORESTANDARDS.ORG/MATH/CONTENT/8/EE/C/8/B/)
Solve systems of two linear equations in two variables algebraically, and estimate solutions by graphing the equations. Solve
simple cases by inspection. For example, 3x + 2y = 5 and 3x + 2y = 6 have no solution because 3x + 2y cannot simultaneously
be 5 and 6.
CCSS.MATH.CONTENT.8.EE.C.8.C (HTTP://WWW.CORESTANDARDS.ORG/MATH/CONTENT/8/EE/C/8/C/)
Solve real-world and mathematical problems leading to two linear equations in two variables. For example, given coordinates
for two pairs of points, determine whether the line through the first pair of points intersects the line through the second pair.
Grade 8 Functions
Standards in this domain:
CCSS.MATH.CONTENT.8.F.A.1 CCSS.MATH.CONTENT.8.F.A.2 CCSS.MATH.CONTENT.8.F.A.3
CCSS.MATH.CONTENT.8.F.B.4 CCSS.MATH.CONTENT.8.F.B.5
Define, evaluate, and compare functions.
CCSS.MATH.CONTENT.8.F.A.1 (HTTP://WWW.CORESTANDARDS.ORG/MATH/CONTENT/8/F/A/1/)
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.
CCSS.MATH.CONTENT.8.F.A.2 (HTTP://WWW.CORESTANDARDS.ORG/MATH/CONTENT/8/F/A/2/)
Compare properties of two functions each represented in a different way (algebraically, graphically, numerically in tables, or by
verbal descriptions). For example, given a linear function represented by a table of values and a linear function represented by an
algebraic expression, determine which function has the greater rate of change.
CCSS.MATH.CONTENT.8.F.A.3 (HTTP://WWW.CORESTANDARDS.ORG/MATH/CONTENT/8/F/A/3/)
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. For example, the function A = s giving the area of a square as a function of its side length is not linear because its
graph contains the points (1,1), (2,4) and (3,9), which are not on a straight line.
Use functions to model relationships between quantities.
6/10/2019 Grade 8 » Functions | Common Core State Standards Initiative
www.corestandards.org/Math/Content/8/F/ 2/2
CCSS.MATH.CONTENT.8.F.B.4 (HTTP://WWW.CORESTANDARDS.ORG/MATH/CONTENT/8/F/B/4/)
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.
CCSS.MATH.CONTENT.8.F.B.5 (HTTP://WWW.CORESTANDARDS.ORG/MATH/CONTENT/8/F/B/5/)
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.
1 Function notation is not required for Grade 8.
Grade 8 Geometry
Standards in this domain:
CCSS.MATH.CONTENT.8.G.A.1 CCSS.MATH.CONTENT.8.G.A.2 CCSS.MATH.CONTENT.8.G.A.3
CCSS.MATH.CONTENT.8.G.A.4 CCSS.MATH.CONTENT.8.G.A.5 CCSS.MATH.CONTENT.8.G.B.6
CCSS.MATH.CONTENT.8.G.B.7 CCSS.MATH.CONTENT.8.G.B.8 CCSS.MATH.CONTENT.8.G.C.9
Understand congruence and similarity using physical models, transparencies, or geometry software.
CCSS.MATH.CONTENT.8.G.A.1 (HTTP://WWW.CORESTANDARDS.ORG/MATH/CONTENT/8/G/A/1/)
Verify experimentally the properties of rotations, reflections, and translations:
CCSS.MATH.CONTENT.8.G.A.1.A (HTTP://WWW.CORESTANDARDS.ORG/MATH/CONTENT/8/G/A/1/A/)
Lines are taken to lines, and line segments to line segments of the same length.
CCSS.MATH.CONTENT.8.G.A.1.B (HTTP://WWW.CORESTANDARDS.ORG/MATH/CONTENT/8/G/A/1/B/)
Angles are taken to angles of the same measure.
CCSS.MATH.CONTENT.8.G.A.1.C (HTTP://WWW.CORESTANDARDS.ORG/MATH/CONTENT/8/G/A/1/C/)
Parallel lines are taken to parallel lines.
CCSS.MATH.CONTENT.8.G.A.2 (HTTP://WWW.CORESTANDARDS.ORG/MATH/CONTENT/8/G/A/2/)
Understand that a two-dimensional figure is congruent to another if the second can be obtained from the first by a sequence of rotations, reflections, and translations; given two congruent figures, describe a sequence that exhibits the congruence between them.
CCSS.MATH.CONTENT.8.G.A.3 (HTTP://WWW.CORESTANDARDS.ORG/MATH/CONTENT/8/G/A/3/)
Describe the effect of dilations, translations, rotations, and reflections on two-dimensional figures using coordinates.
CCSS.MATH.CONTENT.8.G.A.4 (HTTP://WWW.CORESTANDARDS.ORG/MATH/CONTENT/8/G/A/4/)
Understand that a two-dimensional figure is similar to another if the second can be obtained from the first by a sequence of
rotations, reflections, translations, and dilations; given two similar two-dimensional figures, describe a sequence that exhibits the
similarity between them.
CCSS.MATH.CONTENT.8.G.A.5 (HTTP://WWW.CORESTANDARDS.ORG/MATH/CONTENT/8/G/A/5/)
Use informal arguments to establish facts about the angle sum and exterior angle of triangles, about the angles created when
parallel lines are cut by a transversal, and the angle-angle criterion for similarity of triangles. For example, arrange three copies of
the same triangle so that the sum of the three angles appears to form a line, and give an argument in terms of transversals why
this is so.
Understand and apply the Pythagorean Theorem.
CCSS.MATH.CONTENT.8.G.B.6 (HTTP://WWW.CORESTANDARDS.ORG/MATH/CONTENT/8/G/B/6/)
Explain a proof of the Pythagorean Theorem and its converse.
CCSS.MATH.CONTENT.8.G.B.7 (HTTP://WWW.CORESTANDARDS.ORG/MATH/CONTENT/8/G/B/7/)
Apply the Pythagorean Theorem to determine unknown side lengths in right triangles in real-world and mathematical problems in
two and three dimensions.
CCSS.MATH.CONTENT.8.G.B.8 (HTTP://WWW.CORESTANDARDS.ORG/MATH/CONTENT/8/G/B/8/)
Apply the Pythagorean Theorem to find the distance between two points in a coordinate system.
Solve real-world and mathematical problems involving volume of cylinders, cones, and spheres.
CCSS.MATH.CONTENT.8.G.C.9 (HTTP://WWW.CORESTANDARDS.ORG/MATH/CONTENT/8/G/C/9/)
Know the formulas for the volumes of cones, cylinders, and spheres and use them to solve real-world and mathematical problems.
Grade 8 Statistics & Probability
Standards in this domain:
CCSS.MATH.CONTENT.8.SP.A.1 CCSS.MATH.CONTENT.8.SP.A.2 CCSS.MATH.CONTENT.8.SP.A.3
CCSS.MATH.CONTENT.8.SP.A.4
Investigate patterns of association in bivariate data.
CCSS.MATH.CONTENT.8.SP.A.1 (HTTP://WWW.CORESTANDARDS.ORG/MATH/CONTENT/8/SP/A/1/)
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.
CCSS.MATH.CONTENT.8.SP.A.2 (HTTP://WWW.CORESTANDARDS.ORG/MATH/CONTENT/8/SP/A/2/)
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.
CCSS.MATH.CONTENT.8.SP.A.3 (HTTP://WWW.CORESTANDARDS.ORG/MATH/CONTENT/8/SP/A/3/)
Use the equation of a linear model to solve problems in the context of bivariate measurement data, interpreting the slope and
intercept. For example, in a linear model for a biology experiment, interpret a slope of 1.5 cm/hr as meaning that an additional
hour of sunlight each day is associated with an additional 1.5 cm in mature plant height.
CCSS.MATH.CONTENT.8.SP.A.4 (HTTP://WWW.CORESTANDARDS.ORG/MATH/CONTENT/8/SP/A/4/)
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. For example, collect data from students in your class on whether or not they have a curfew on school nights and
whether or not they have assigned chores at home. Is there evidence that those who have a curfew also tend to have chores?