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Texas Standards

8th Grade Math TEKS

All 52 Texas math standards for 8th grade, each explained in plain English. The official wording is one click away under each one.

52 standards

Mathematical process standards

7 standards
The student uses mathematical processes to acquire and demonstrate mathematical understanding.
8.1(A)
Use math to tackle problems from daily life, society and the workplace, like comparing two cell phone plans.
Official wording
apply mathematics to problems arising in everyday life, society, and the workplace;
8.1(B)
Solve problems step by step by reading the facts, planning, solving, defending the answer and judging whether it is reasonable.
Official wording
use a problem-solving model that incorporates analyzing given information, formulating a plan or strategy, determining a solution, justifying the solution, and evaluating the problem-solving process and the reasonableness of the solution;
8.1(C)
Decide which tools and methods fit a problem, like graph paper, a graphing calculator, estimation or mental math.
Official wording
select tools, including real objects, manipulatives, paper and pencil, and technology as appropriate, and techniques, including mental math, estimation, and number sense as appropriate, to solve problems;
8.1(D)
Explain math ideas and their consequences with symbols, diagrams, graphs and words, like describing a scatterplot trend in a sentence.
Official wording
communicate mathematical ideas, reasoning, and their implications using multiple representations, including symbols, diagrams, graphs, and language as appropriate;
8.1(E)
Create tables, graphs and diagrams to organize and present math ideas, like a table of values for a linear function.
Official wording
create and use representations to organize, record, and communicate mathematical ideas;
8.1(F)
Study how math ideas relate to one another and use those links to explain, like connecting slope with unit rate.
Official wording
analyze mathematical relationships to connect and communicate mathematical ideas; and
8.1(G)
Explain and defend math arguments in writing or out loud using exact terms, like function, slope and transformation.
Official wording
display, explain, and justify mathematical ideas and arguments using precise mathematical language in written or oral communication.

Number and operations

4 standards
The student applies mathematical process standards to represent and use real numbers in a variety of forms.
8.2(A)
Use a diagram to show how natural numbers, whole numbers, integers, rational and irrational numbers fit inside the real numbers.
Official wording
extend previous knowledge of sets and subsets using a visual representation to describe relationships between sets of real numbers;
8.2(B)
Estimate irrational numbers like π and square roots of numbers under 225 and place those estimates on a number line, like √50 near 7.1.
Official wording
approximate the value of an irrational number, including π and square roots of numbers less than 225, and locate that rational number approximation on a number line;
8.2(C)
Convert numbers between standard form and scientific notation, like 45,000 = 4.5 × 10⁴ and 0.003 = 3 × 10⁻³.
Official wording
convert between standard decimal notation and scientific notation; and
8.2(D)
Put a set of real numbers in order, including irrational ones, like ranking √10, 3.2 and π from least to greatest.
Official wording
order a set of real numbers arising from mathematical and real-world contexts.

Proportionality

15 standards
The student applies mathematical process standards to use proportional relationships to describe dilations.
8.3(A)
Explain that matching sides of similar shapes, including a shape and its dilation, always share the same ratio.
Official wording
generalize that the ratio of corresponding sides of similar shapes are proportional, including a shape and its dilation;
8.3(B)
Compare a shape with its dilation on a coordinate plane to see what changes, like side lengths, and what stays the same, like angles.
Official wording
compare and contrast the attributes of a shape and its dilation(s) on a coordinate plane; and
8.3(C)
Use an algebra rule, like multiplying each coordinate by 3, to explain how a positive scale factor centered at the origin resizes a figure.
Official wording
use an algebraic representation to explain the effect of a given positive rational scale factor applied to two-dimensional figures on a coordinate plane with the origin as the center of dilation.
The student applies mathematical process standards to explain proportional and non-proportional relationships involving slope.
8.4(A)
Use similar right triangles to show that slope, the change in y over the change in x, is the same between any two points on a line.
Official wording
use similar right triangles to develop an understanding that slope, m, given as the rate comparing the change in y-values to the change in x-values, (y2 - y1 )/ (x2 - x1 ), is the same for any two points (x1 , y1 ) and (x2 , y2 ) on the same line;
8.4(B)
Graph a proportional relationship and see the unit rate as how steep its line is, like $12 per hour making a slope of 12.
Official wording
graph proportional relationships, interpreting the unit rate as the slope of the line that models the relationship; and
8.4(C)
Find the slope and y-intercept from a table or graph in math and real situations, like a $25 starting fee plus $10 per month.
Official wording
use data from a table or graph to determine the rate of change or slope and y-intercept in mathematical and real-world problems.
The student applies mathematical process standards to use proportional and non-proportional relationships to develop foundational concepts of functions.
8.5(A)
Model proportional situations in tables, graphs and equations of the form y = kx, such as $9 earned for each hour worked.
Official wording
represent linear proportional situations with tables, graphs, and equations in the form of y = kx;
8.5(B)
Model linear situations that are not proportional with tables, graphs and equations like y = mx + b with b not zero, such as a $5 fee plus $2 per ride.
Official wording
represent linear non-proportional situations with tables, graphs, and equations in the form of y = mx + b, where b ≠ 0;
8.5(C)
Tell from a graph whether a set of paired data looks linear or not, like comparing two scatterplots side by side.
Official wording
contrast bivariate sets of data that suggest a linear relationship with bivariate sets of data that do not suggest a linear relationship from a graphical representation;
8.5(D)
Draw a trend line through paired data and use it to make predictions, like estimating a test score from hours studied.
Official wording
use a trend line that approximates the linear relationship between bivariate sets of data to make predictions;
8.5(E)
Solve direct variation problems, where one quantity is a constant multiple of another, like pay that doubles when hours double.
Official wording
solve problems involving direct variation;
8.5(F)
Decide if a situation is proportional or not by checking its table, graph or equation, like y = 3x versus y = 3x + 2.
Official wording
distinguish between proportional and non-proportional situations using tables, graphs, and equations in the form y = kx or y = mx + b, where b ≠ 0;
8.5(G)
Decide whether a relation is a function from ordered pairs, tables, mapping diagrams and graphs, like checking that each input has one output.
Official wording
identify functions using sets of ordered pairs, tables, mappings, and graphs;
8.5(H)
Find examples of proportional and non-proportional functions in math and real life, like a per-mile fare versus one with a base charge.
Official wording
identify examples of proportional and non-proportional functions that arise from mathematical and real-world problems; and
8.5(I)
Write a y = mx + b equation for a linear relationship given in words, numbers, a table or a graph, like a plant that starts at 3 cm and grows 2 cm a week.
Official wording
write an equation in the form y = mx + b to model a linear relationship between two quantities using verbal, numerical, tabular, and graphical representations.

Expressions, equations, and relationships

12 standards
The student applies mathematical process standards to develop mathematical relationships and make connections to geometric formulas.
8.6(A)
Describe the cylinder volume formula V = Bh as the area of the circle base times the height.
Official wording
describe the volume formula V = Bh of a cylinder in terms of its base area and its height;
8.6(B)
Use models to show a cone holds one third the volume of a cylinder with the same base and height, and tie this to their formulas.
Official wording
model the relationship between the volume of a cylinder and a cone having both congruent bases and heights and connect that relationship to the formulas; and
8.6(C)
Explain the Pythagorean theorem with models and diagrams, like squares built on each side of a right triangle.
Official wording
use models and diagrams to explain the Pythagorean theorem.
The student applies mathematical process standards to use geometry to solve problems.
8.7(A)
Find how much cylinders, cones and spheres hold to solve problems, like the amount of water in a can or air in a ball.
Official wording
solve problems involving the volume of cylinders, cones, and spheres;
8.7(B)
Build on surface area work to find lateral and total surface area of rectangular prisms, triangular prisms and cylinders, like a can's label.
Official wording
use previous knowledge of surface area to make connections to the formulas for lateral and total surface area and determine solutions for problems involving rectangular prisms, triangular prisms, and cylinders;
8.7(C)
Apply the Pythagorean theorem and its converse to real problems, like finding how high a ladder reaches or testing if a corner is square.
Official wording
use the Pythagorean Theorem and its converse to solve problems; and
8.7(D)
Use the Pythagorean theorem to find how far apart two points on a coordinate grid are, by drawing a right triangle between them.
Official wording
determine the distance between two points on a coordinate plane using the Pythagorean Theorem.
The student applies mathematical process standards to use one-variable equations or inequalities in problem situations.
8.8(A)
Turn a problem into an equation or inequality with the variable on both sides, using fractions, decimals or negatives, like 2.5x + 10 = 4x.
Official wording
write one-variable equations or inequalities with variables on both sides that represent problems using rational number coefficients and constants;
8.8(B)
Write a real-world story to match an equation or inequality with the variable on both sides, like two gyms with different fees for 20 + 5x = 35 + 2x.
Official wording
write a corresponding real-world problem when given a one-variable equation or inequality with variables on both sides of the equal sign using rational number coefficients and constants;
8.8(C)
Model and solve equations with the variable on both sides using fractions, decimals and negatives, like 0.5x + 6 = 2x - 3.
Official wording
model and solve one-variable equations with variables on both sides of the equal sign that represent mathematical and real-world problems using rational number coefficients and constants; and
8.8(D)
Give informal reasons for facts about a triangle's angle sum and exterior angles, parallel lines cut by a transversal, and why two equal angles make triangles similar.
Official wording
use informal arguments to establish facts about the angle sum and exterior angle of triangles, the angles created when parallel lines are cut by a transversal, and the angle-angle criterion for similarity of triangles.
The student applies mathematical process standards to use multiple representations to develop foundational concepts of simultaneous linear equations.
8.9
Find and check the x and y values that make two linear equations true at once by locating where their graphs cross.
Official wording
identify and verify the values of x and y that simultaneously satisfy two linear equations in the form y = mx + b from the intersections of the graphed equations.

Two-dimensional shapes

4 standards
The student applies mathematical process standards to develop transformational geometry concepts.
8.10(A)
Work out general rules for how rotations, reflections, translations and dilations change a shape's orientation and size on a coordinate plane.
Official wording
generalize the properties of orientation and congruence of rotations, reflections, translations, and dilations of two-dimensional shapes on a coordinate plane;
8.10(B)
Sort transformations into those that keep a shape the same size and shape, like slides and flips, and those that do not, like dilations.
Official wording
differentiate between transformations that preserve congruence and those that do not;
8.10(C)
Use coordinate rules to explain slides, flips over the x- or y-axis and turns of 90°, 180°, 270° or 360°, like a flip over the x-axis changing y to -y.
Official wording
explain the effect of translations, reflections over the x- or y-axis, and rotations limited to 90°, 180°, 270°, and 360° as applied to two-dimensional shapes on a coordinate plane using an algebraic representation; and
8.10(D)
Model how a dilation changes lengths and areas, like a scale factor of 3 making sides 3 times longer and the area 9 times larger.
Official wording
model the effect on linear and area measurements of dilated two-dimensional shapes.

Measurement and data

3 standards
The student applies mathematical process standards to use statistical procedures to describe data.
8.11(A)
Make a scatterplot and describe whether the paired data show a linear, nonlinear or no association, like height and shoe size.
Official wording
construct a scatterplot and describe the observed data to address questions of association such as linear, non-linear, and no association between bivariate data;
8.11(B)
Find the mean absolute deviation of up to 10 data values and use it to describe how far, on average, the values sit from the mean.
Official wording
determine the mean absolute deviation and use this quantity as a measure of the average distance data are from the mean using a data set of no more than 10 data points; and
8.11(C)
Run simulations that pull many equal-sized random samples from a population you know to see how well a random sample mirrors the whole group.
Official wording
simulate generating random samples of the same size from a population with known characteristics to develop the notion of a random sample being representative of the population from which it was selected.

Personal financial literacy

7 standards
The student applies mathematical process standards to develop an economic way of thinking and problem solving useful in one's life as a knowledgeable consumer and investor.
8.12(A)
Solve real problems showing how the interest rate and the length of a loan change the total cost of borrowing, like a car loan over 3 or 5 years.
Official wording
solve real-world problems comparing how interest rate and loan length affect the cost of credit;
8.12(B)
Use an online calculator to find the full cost of paying back loans, including credit cards and quick cash loans, at different rates and lengths of time.
Official wording
calculate the total cost of repaying a loan, including credit cards and easy access loans, under various rates of interest and over different periods using an online calculator;
8.12(C)
Explain how investing small amounts on a regular schedule, like $25 a month for college or retirement, adds up over the years.
Official wording
explain how small amounts of money invested regularly, including money saved for college and retirement, grow over time;
8.12(D)
Compute and compare what an account earns with simple interest versus compound interest, like $500 at 4% for 10 years.
Official wording
calculate and compare simple interest and compound interest earnings;
8.12(E)
Name and explain the pros and cons of different ways to pay, like cash, checks, debit cards, credit cards and layaway.
Official wording
identify and explain the advantages and disadvantages of different payment methods;
8.12(F)
Judge whether choices with money are responsible and name the rewards of responsible money habits and the costs of careless ones.
Official wording
analyze situations to determine if they represent financially responsible decisions and identify the benefits of financial responsibility and the costs of financial irresponsibility; and
8.12(G)
Estimate what two-year and four-year college costs, including the family share, and plan regular savings to cover at least the first year.
Official wording
estimate the cost of a two-year and four-year college education, including family contribution, and devise a periodic savings plan for accumulating the money needed to contribute to the total cost of attendance for at least the first year of college.

The official Texas documents

Texas Essential Knowledge and Skills for Mathematics, 19 Texas Administrative Code Chapter 111, adopted by the Texas State Board of Education.

The plain-English lines are EMStudio's own explanations, shown beside the official wording. They are not part of the standards.