Rational and irrational numbers
Students learn that some numbers, like the square root of 2 or pi, cannot be written as a simple fraction. They place these numbers on a number line and work with square roots and cube roots.
This is the year math becomes about lines and what they predict. Students learn that a straight line on a graph carries a story: a starting point, a steady rate of change, and an equation that ties them together. They solve harder equations, work with square roots, and use the Pythagorean theorem to find missing distances. By spring, students can graph a line from an equation like y = 2x + 3 and explain what the slope means in a real situation.
Students learn that some numbers, like the square root of 2 or pi, cannot be written as a simple fraction. They place these numbers on a number line and work with square roots and cube roots.
Students write very large and very small numbers using powers of ten. They use this to compare things like the distance to a star or the size of a cell, and to read numbers a calculator produces.
Students solve equations and inequalities with the variable on both sides, including ones with fractions and parentheses. They learn when an equation has one answer, no answer, or any number as an answer.
Students study straight lines on a graph and learn that slope tells how fast something changes. They work with the equation y = mx + b and start thinking of a rule as a function with one output for each input.
Students use angle facts to find missing measures, including angles made when parallel lines are crossed by another line. They prove and use the Pythagorean Theorem to find missing sides of right triangles and distances between points.
Students find the volume and surface area of cones, pyramids, and spheres in real situations. They also plot pairs of data on a scatter plot, draw a line that fits the trend, and use it to make predictions.
Two rays that start at the same point form an angle. Students learn to measure angles in degrees and recognize that a larger degree means a wider opening between the rays.
Angles are measured as slices of a circle. A full circle has 360 equal slices, each one a degree, and any angle gets its measure by counting how many of those slices fit inside it.
Angles are measured by how many one-degree turns fit inside them. A 90-degree angle holds exactly 90 of those turns, a 180-degree angle holds 180, and so on.
Students use a protractor to measure angles in whole-number degrees and to draw angles at a specific degree. Both skills show up on diagrams, maps, and any technical drawing students encounter in later math.
When a large angle is split into smaller angles, the parts add up to the whole. Students find missing angle sizes in diagrams by writing a simple addition or subtraction equation.
Given a figure with labeled angles, students find a missing angle by setting up and solving a simple equation. They use angle pair relationships: supplementary angles add to 180 degrees, complementary to 90, and vertical angles match.
Students learn why a triangle's three angles always add up to 180 degrees, what happens to angles when a straight line crosses two parallel lines, and how two triangles with matching angles must be the same shape, just different sizes.
Draw triangles using given angle sizes or side lengths, then figure out whether those measurements produce exactly one possible triangle, several different triangles, or no triangle at all.
Students explain why the Pythagorean Theorem works, not just how to use it. They also show that if a triangle's sides fit the a² + b² = c² pattern, the triangle must have a right angle.
Given two sides of a right triangle, students calculate the missing side using the Pythagorean Theorem. This applies to flat diagrams and real objects like ramps, ladders, or boxes.
Students use the Pythagorean Theorem to find the straight-line distance between two points on a grid. They treat the horizontal and vertical gaps as the two short sides of a right triangle, then solve for the longest side.
Students use formulas to find the curved length of a circle's edge, the area of a pie-slice portion, and the surface area and volume of pointed and rounded 3D shapes like cones and spheres.
Students explore how the formulas for volume and surface area of 3D shapes connect to each other. For example, they look at how a cone, cylinder, and sphere with the same radius are mathematically related.
Students learn why the volume of a pyramid or cone is exactly one-third of the volume of a box or cylinder with the same base and height. They apply that formula to find how much space a pointed shape holds.
Students use the formula SA = B + ½Pl to find the total surface area of pyramids and cones, where B is the base area, P is the base perimeter, and l is the slant height. They apply this to real shapes, not just diagrams.
Students find the area of shapes like pie slices and circles, and calculate the volume or surface area of objects like cones, pyramids, and spheres. These are the formulas that show up in real buildings, containers, and designs.
| Standard | Definition | Code |
|---|---|---|
| Recognize angles as geometric shapes that are formed wherever two rays share a… | Two rays that start at the same point form an angle. Students learn to measure angles in degrees and recognize that a larger degree means a wider opening between the rays. | 8.G.1 |
| An angle is measured with reference to a circle with its center at the common… | Angles are measured as slices of a circle. A full circle has 360 equal slices, each one a degree, and any angle gets its measure by counting how many of those slices fit inside it. | 8.G.1.a |
| An angle that turns through n one-degree angles is said to have an angle… | Angles are measured by how many one-degree turns fit inside them. A 90-degree angle holds exactly 90 of those turns, a 180-degree angle holds 180, and so on. | 8.G.1.b |
| Measure angles in whole-number degrees using a protractor | Students use a protractor to measure angles in whole-number degrees and to draw angles at a specific degree. Both skills show up on diagrams, maps, and any technical drawing students encounter in later math. | 8.G.2 |
| Recognize angle measure as additive | When a large angle is split into smaller angles, the parts add up to the whole. Students find missing angle sizes in diagrams by writing a simple addition or subtraction equation. | 8.G.3 |
| Use facts about supplementary, complementary, vertical | Given a figure with labeled angles, students find a missing angle by setting up and solving a simple equation. They use angle pair relationships: supplementary angles add to 180 degrees, complementary to 90, and vertical angles match. | 8.G.4 |
| Use informal arguments to establish facts about the angle sum and exterior… | Students learn why a triangle's three angles always add up to 180 degrees, what happens to angles when a straight line crosses two parallel lines, and how two triangles with matching angles must be the same shape, just different sizes. | 8.G.5 |
| Draw (freehand, with ruler and protractor | Draw triangles using given angle sizes or side lengths, then figure out whether those measurements produce exactly one possible triangle, several different triangles, or no triangle at all. | 8.G.6 |
| Explain a proof of the Pythagorean Theorem and its converse | Students explain why the Pythagorean Theorem works, not just how to use it. They also show that if a triangle's sides fit the a² + b² = c² pattern, the triangle must have a right angle. | 8.G.7 |
| Apply the Pythagorean Theorem to determine unknown side lengths in right… | Given two sides of a right triangle, students calculate the missing side using the Pythagorean Theorem. This applies to flat diagrams and real objects like ramps, ladders, or boxes. | 8.G.8 |
| Apply the Pythagorean Theorem to find the distance between two points in a… | Students use the Pythagorean Theorem to find the straight-line distance between two points on a grid. They treat the horizontal and vertical gaps as the two short sides of a right triangle, then solve for the longest side. | 8.G.9 |
| Use the formulas or informal reasoning to find the arc length, areas of… | Students use formulas to find the curved length of a circle's edge, the area of a pie-slice portion, and the surface area and volume of pointed and rounded 3D shapes like cones and spheres. | 8.G.10 |
| Investigate the relationship between the formulas of three dimensional… | Students explore how the formulas for volume and surface area of 3D shapes connect to each other. For example, they look at how a cone, cylinder, and sphere with the same radius are mathematically related. | 8.G.11 |
| Generalize the volume formula for pyramids and cones | Students learn why the volume of a pyramid or cone is exactly one-third of the volume of a box or cylinder with the same base and height. They apply that formula to find how much space a pointed shape holds. | 8.G.11.a |
| Generalize surface area formula of pyramids and cones | Students use the formula SA = B + ½Pl to find the total surface area of pyramids and cones, where B is the base area, P is the base perimeter, and l is the slant height. They apply this to real shapes, not just diagrams. | 8.G.11.b |
| Solve real-world and mathematical problems involving arc length, area of… | Students find the area of shapes like pie slices and circles, and calculate the volume or surface area of objects like cones, pyramids, and spheres. These are the formulas that show up in real buildings, containers, and designs. | 8.G.12 |
Rational numbers (like fractions and whole numbers) turn into decimals that either stop or repeat a pattern forever. Irrational numbers, like the square root of 2, go on forever with no repeating pattern. Students learn to tell the difference and convert repeating decimals back into fractions.
Students learn to place numbers like pi or square roots at roughly the right spot on a number line by finding the two familiar fractions or decimals they fall between. They use that same method to estimate the value of expressions.
| Standard | Definition | Code |
|---|---|---|
| Know that numbers that are not rational are called irrational | Rational numbers (like fractions and whole numbers) turn into decimals that either stop or repeat a pattern forever. Irrational numbers, like the square root of 2, go on forever with no repeating pattern. Students learn to tell the difference and convert repeating decimals back into fractions. | 8.NS.1 |
| Use rational approximations of irrational numbers to compare the size of… | Students learn to place numbers like pi or square roots at roughly the right spot on a number line by finding the two familiar fractions or decimals they fall between. They use that same method to estimate the value of expressions. | 8.NS.2 |
Students learn to find the square root and cube root of whole numbers, like recognizing that the square root of 25 is 5. They also learn why some roots, like the square root of 2, cannot be written as a clean fraction.
Students learn to write very large or very small numbers using powers of 10, like 3 × 10⁶ for three million. They also compare those numbers to see how many times bigger one is than the other.
Scientific notation is shorthand for writing very large or very small numbers using powers of 10. Students convert between this shorthand and ordinary numbers, pick units that fit the scale of what they're measuring, and read the notation a calculator or spreadsheet produces.
Students graph a proportional relationship as a straight line and identify the unit rate as the slope. They also compare two proportional relationships that may be shown in different forms, like a table and a graph.
Students learn why a straight line has the same steepness everywhere, then use that idea to write the equation of a line. They practice finding slope from two points on a graph and building equations like y = mx + b.
A line through the origin follows y = mx. Adding a number shifts that whole line up or down without changing its steepness. Students explain why y = mx + b describes the same slant, just starting from a different height.
Students solve equations and inequalities that take one step or several steps to work out, including problems where the same unknown number appears on both sides of the equals sign. The goal is accuracy and speed.
Solving a one-variable equation leads to exactly one answer, no answer, or every number working. Students simplify the equation step by step until it becomes clear which case they have.
Students solve equations and inequalities where the numbers involved are fractions or decimals. They simplify both sides first by distributing and combining similar terms, then find the value that makes the equation or inequality true.
| Standard | Definition | Code |
|---|---|---|
| Use square root and cube root symbols to represent solutions to equations of… | Students learn to find the square root and cube root of whole numbers, like recognizing that the square root of 25 is 5. They also learn why some roots, like the square root of 2, cannot be written as a clean fraction. | 8.EE.1 |
| Use numbers expressed in the form of a single digit times an integer power of… | Students learn to write very large or very small numbers using powers of 10, like 3 × 10⁶ for three million. They also compare those numbers to see how many times bigger one is than the other. | 8.EE.2 |
| Read and write numbers expressed in scientific notation, including problems… | Scientific notation is shorthand for writing very large or very small numbers using powers of 10. Students convert between this shorthand and ordinary numbers, pick units that fit the scale of what they're measuring, and read the notation a calculator or spreadsheet produces. | 8.EE.3 |
| Graph proportional relationships, interpreting its unit rate as the slope | Students graph a proportional relationship as a straight line and identify the unit rate as the slope. They also compare two proportional relationships that may be shown in different forms, like a table and a graph. | 8.EE.4 |
| Use similar triangles to explain why the slope | Students learn why a straight line has the same steepness everywhere, then use that idea to write the equation of a line. They practice finding slope from two points on a graph and building equations like y = mx + b. | 8.EE.5 |
| Describe the relationship between the proportional relationship expressed in y… | A line through the origin follows y = mx. Adding a number shifts that whole line up or down without changing its steepness. Students explain why y = mx + b describes the same slant, just starting from a different height. | 8.EE.6 |
| Fluently (efficiently, accurately | Students solve equations and inequalities that take one step or several steps to work out, including problems where the same unknown number appears on both sides of the equals sign. The goal is accuracy and speed. | 8.EE.7 |
| Give examples of linear equations in one variable with one solution | Solving a one-variable equation leads to exactly one answer, no answer, or every number working. Students simplify the equation step by step until it becomes clear which case they have. | 8.EE.7.a |
| Solve linear equations and inequalities with rational number coefficients… | Students solve equations and inequalities where the numbers involved are fractions or decimals. They simplify both sides first by distributing and combining similar terms, then find the value that makes the equation or inequality true. | 8.EE.7.b |
Students plot two real-world measurements on a graph to see how they relate. They look for patterns like upward or downward trends, tightly grouped clusters, and data points that sit far from the rest.
When a scatter plot shows data trending in a line, students draw a best-fit line through the points by eye and judge how well it fits by checking how close the points are to that line.
Students use the equation of a line drawn through a scatterplot to answer real-world questions. They explain what the slope and starting point of that line mean in plain terms, like how much a price rises for each extra year.
| Standard | Definition | Code |
|---|---|---|
| Construct and interpret scatter plots for bivariate measurement data to… | Students plot two real-world measurements on a graph to see how they relate. They look for patterns like upward or downward trends, tightly grouped clusters, and data points that sit far from the rest. | 8.SP.1 |
| Know that straight lines are widely used to model relationships between two… | When a scatter plot shows data trending in a line, students draw a best-fit line through the points by eye and judge how well it fits by checking how close the points are to that line. | 8.SP.2 |
| Use the equation of a linear model to solve problems in the context of… | Students use the equation of a line drawn through a scatterplot to answer real-world questions. They explain what the slope and starting point of that line mean in plain terms, like how much a price rises for each extra year. | 8.SP.3 |
A function is a rule where every input has exactly one output. Students read graphs as a list of input-output pairs, and explain why each input can only point to one result.
Two linear functions might be shown as an equation, a graph, a table, or a written description. Students compare the two, spotting differences in slope or starting value no matter which form they see.
Students learn that y=mx+b always makes a straight line on a graph. They also identify functions that curve or bend, which means those functions are not linear.
Students find the starting value and steady rate of change in a linear relationship, then write an equation that models it. They read those values from a table, a graph, or a word problem and explain what each number means in context.
Students read a graph to describe how two quantities relate, noting where a line rises, falls, or curves. They also sketch a rough graph to match a verbal description, like "the car sped up, then stopped."
| Standard | Definition | Code |
|---|---|---|
| Explain that a function is a rule that assigns to each input exactly one output | A function is a rule where every input has exactly one output. Students read graphs as a list of input-output pairs, and explain why each input can only point to one result. | 8.F.1 |
| Compare properties of two linear functions represented in a variety of ways | Two linear functions might be shown as an equation, a graph, a table, or a written description. Students compare the two, spotting differences in slope or starting value no matter which form they see. | 8.F.2 |
| Interpret the equation y=mx+b as defining a linear function, whose graph is a… | Students learn that y=mx+b always makes a straight line on a graph. They also identify functions that curve or bend, which means those functions are not linear. | 8.F.3 |
| Construct a function to model a linear relationship between two quantities | Students find the starting value and steady rate of change in a linear relationship, then write an equation that models it. They read those values from a table, a graph, or a word problem and explain what each number means in context. | 8.F.4 |
| Describe qualitatively the functional relationship between two quantities by… | Students read a graph to describe how two quantities relate, noting where a line rises, falls, or curves. They also sketch a rough graph to match a verbal description, like "the car sped up, then stopped." | 8.F.5 |
KAP mathematics assessment for grades 3 through 8 and grade 10, aligned to the Kansas Mathematics Standards.
Federally administered sample-based assessment in reading, mathematics, science, writing, and other subjects. NAEP results inform state-by-state comparisons rather than individual student or school accountability.
By spring, students solve multi-step equations with variables on both sides, graph lines using slope and y-intercept, and apply the Pythagorean Theorem to find missing side lengths. They also work with scientific notation for very large and very small numbers, and find volumes of cones, cylinders, and spheres.
Ask students to explain each step out loud while solving a problem. If they get stuck, have them rewrite the equation on a fresh line instead of erasing. Most mistakes this year come from rushing through distribution or combining like terms, not from misunderstanding the math.
Slope is how steep a line is, or how much one thing changes when another changes by one. A phone plan that costs five dollars more for every extra gigabyte has a slope of five. Pointing out slope in real situations like gas mileage or pay rates helps the idea stick.
A common path starts with rational and irrational numbers, moves into exponents and scientific notation, then builds equations and functions through slope and linear models. Geometry, the Pythagorean Theorem, and volume usually anchor the spring, with scatter plots woven in once students are comfortable with linear functions.
Slope as a rate of change, solving equations with variables on both sides, and the difference between proportional and non-proportional linear relationships tend to need extra time. Scientific notation operations also trip students up, especially when the exponents are negative.
Look for right angles around the house, like a TV screen, a door, or a piece of paper. Ask how long the diagonal would be if you knew the two sides. Doing this with a tape measure once or twice makes the formula feel like a tool instead of a memorized rule.
Students should move between four representations of a linear function: a verbal description, a table, an equation, and a graph. Given any one, they can produce the others and explain what the slope and starting value mean in context.
Readiness shows up when students solve linear equations without prompting, graph y = mx + b from scratch, and recognize when a relationship is not linear. Comfort with square roots, cube roots, and the Pythagorean Theorem also signals they are ready for algebra and geometry coursework.