Skip to content
PlayOwl

Find a course

Search every subject world, from Preschool to Grade 12. The first five courses of every subject path are free.

24 courses

Courses found

Mathematics · Grade 8

Rational and Irrational Numbers

Learners use long division to see why every fraction becomes a decimal that stops or repeats, and then run the process backwards to turn repeating decimals into fractions. They solve x^2^ = p and x^3^ = p with square and cube roots, meet numbers such as √2 and π that are not fractions at all, and squeeze those irrational numbers between rational ones to place and compare them on the number line.

  • 4 lessons
  • About 90 min
  • Quiz: 10 questions
Free starter

Mathematics · Grade 8

Exponents and Scientific Notation

Learners explain the properties of integer exponents by counting factors, extend them to zero and negative exponents with patterns and the quotient rule, and then use powers of ten to write very large and very small quantities in scientific notation. They compare magnitudes by asking how many times as much, and multiply, divide, add and subtract in scientific notation, including calculator E-notation and sensible units.

  • 4 lessons
  • About 90 min
  • Quiz: 10 questions
Free starter

Mathematics · Grade 8

Proportional Relationships and Slope

Learners connect the unit rate of a proportional relationship to the slope of its graph and compare proportional relationships given as equations, tables, graphs and descriptions. They use slope triangles and similar triangles to explain why a line has one constant slope, compute slopes from two points, and derive and graph y = mx and y = mx + b.

  • 4 lessons
  • About 95 min
  • Quiz: 10 questions
Free starter

Mathematics · Grade 8

Linear Equations and Reasoning

Learners solve linear equations with the variable on both sides, naming the property of equality behind every step. They distribute and combine like terms, clear fractions and decimals, and use the structure of an equation to decide whether it has exactly one solution, no solution or infinitely many solutions.

  • 4 lessons
  • About 90 min
  • Quiz: 10 questions
Free starter

Mathematics · Grade 8

Systems of Linear Equations

Learners see the solution of a system of two linear equations as the point that lies on both lines, check ordered pairs in both equations and solve systems by graphing. They use slopes and intercepts to recognise systems with no solution or infinitely many solutions, solve by substitution, elimination and inspection, and model real situations with systems whose solutions they interpret in context.

  • 4 lessons
  • About 95 min
  • Quiz: 10 questions
Free starter

Mathematics · Grade 8

Functions and Multiple Representations

Learners define a function as a rule that gives each input exactly one output and test relations given as pairs, tables, graphs and descriptions. They find and interpret the rate of change and initial value of linear functions, compare functions shown in different representations, tell linear from nonlinear functions, and read and describe qualitative graphs.

  • 5 lessons
  • About 100 min
  • Quiz: 11 questions

Mathematics · Grade 8

Transformations and Congruence

Learners study the three rigid motions (translations, reflections and rotations), verify that they keep lengths, angle measures and parallel lines, and describe them with coordinate rules, including reflections across the axes and 90° and 180° rotations about the origin. The course ends by defining congruence as a sequence of rigid motions and by finding and checking such sequences.

  • 4 lessons
  • About 90 min
  • Quiz: 10 questions

Mathematics · Grade 8

Similarity and Angle Relationships

Learners describe dilations with coordinates and scale factors, define similarity as rigid motions plus dilations, and use scale factors to find missing lengths. They then find angles formed when parallel lines are cut by a transversal, explain why a triangle's angles add to 180° and why an exterior angle equals the sum of the two remote interior angles, and use the angle-angle criterion to prove triangles similar and solve measurement problems.

  • 4 lessons
  • About 95 min
  • Quiz: 10 questions

Mathematics · Grade 8

The Pythagorean Theorem

Learners see why a^2^ + b^2^ = c^2^ through an area argument with squares, and use the converse to test whether a triangle has a right angle. They then find missing sides of right triangles in real situations, extend the theorem to the space diagonal of a box, and compute distances between points on the coordinate plane, giving exact square roots or rounded values as asked.

  • 4 lessons
  • About 90 min
  • Quiz: 10 questions

Mathematics · Grade 8

Volume of Cylinders, Cones and Spheres

Learners extend base-times-height to cylinders, discover that a cone holds one third of the matching cylinder, and find sphere volumes with the 1 : 2 : 3 relationship among a cone, a sphere and a cylinder. They give exact answers in terms of π and approximate answers with π ≈ 3.14, then work backward to missing heights and radii (using square and cube roots) and find the volume of composite solids in real situations.

  • 4 lessons
  • About 90 min
  • Quiz: 10 questions

Mathematics · Grade 8

Scatter Plots and Two-Variable Data

Learners plot paired data and describe the pattern in a scatter plot: direction, linear or nonlinear form, clusters and outliers, without confusing association with cause. They fit straight lines informally and judge them by how close the points are, use a line's equation to predict and to interpret slope and intercept in context, and finish with two-way tables, using relative frequencies to decide whether two categorical variables seem associated.

  • 4 lessons
  • About 95 min
  • Quiz: 10 questions

Mathematics · Grade 8

Model, Explain and Prepare for Algebra

This capstone pulls the year together for algebra. Learners build linear models from descriptions, tables and two points, solve and critique linear equations (including ones with no or infinitely many solutions), and model real choices with systems of equations. They then use the Pythagorean theorem in context, critique predictions made far outside the data, and retrieve exponent, scientific-notation and function skills from earlier in the year.

  • 4 lessons
  • About 100 min
  • Quiz: 11 questions

Mathematics · Grade 9

Algebra Readiness and Quantitative Reasoning

A fast but serious consolidation of the number sense algebra depends on: computing with signed rational numbers and proving why the sign rules work, reasoning with ratios and unit rates, handling percent change (including why successive changes do not simply add), and checking whether a quantitative result or claim is reasonable.

  • 4 lessons
  • About 110 min
  • Quiz: 10 questions
Free starter

Mathematics · Grade 9

Expressions, Units and Structure

Learners write expressions from words and contexts and read the meaning of each part, use the properties of operations to produce and justify equivalent expressions (and to disprove false equivalences with counterexamples), evaluate formulas carefully, and use units and dimensional analysis to convert quantities and check that formulas make sense.

  • 4 lessons
  • About 110 min
  • Quiz: 11 questions
Free starter

Mathematics · Grade 9

Linear Equations and Inequalities

Learners solve multi-step linear equations as chains of justified moves, recognize equations with no solution or infinitely many, rearrange formulas, and solve linear and compound inequalities, including a clear explanation of why multiplying by a negative reverses the inequality. The course ends by modeling budgets, capacities and schedules with equations and inequalities and interpreting the answers in context.

  • 4 lessons
  • About 120 min
  • Quiz: 11 questions
Free starter

Mathematics · Grade 9

Coordinate Graphs and Rate of Change

Learners read the story a graph tells, compute slope from points, tables and graphs and interpret it as a rate with units, write and graph lines in slope-intercept, point-slope and standard form (including horizontal and vertical lines), and measure the average rate of change of curved relationships over an interval.

  • 4 lessons
  • About 115 min
  • Quiz: 11 questions
Free starter

Mathematics · Grade 9

Functions and Their Representations

Learners define a function as a rule that gives each input exactly one output and test relations in mappings, tables, graphs and equations. They use function notation to evaluate and interpret statements like h(2) = 30, describe domain, range and key features of graphs, and compare functions given in different representations, including arithmetic sequences seen as linear functions.

  • 4 lessons
  • About 115 min
  • Quiz: 11 questions
Free starter

Mathematics · Grade 9

Linear Models and Interpretation

Learners connect the table, equation, graph and words of a linear model, interpret rate of change and initial value with their units, and build models from two facts while checking that every representation agrees. They then decide when a prediction is trustworthy, spot invalid extrapolations, and finish with the full cycle of graphing, solving and interpreting. An optional honors lesson critiques two plausible models of a cooling cup of tea.

  • 5 lessons
  • About 120 min
  • Quiz: 10 questions

Mathematics · Grade 9

Systems of Equations and Inequalities

Learners solve pairs of linear equations by graphing, substitution and elimination, prove why elimination is valid, and classify systems by their number of solutions. They model ticket sales, mixtures and plan comparisons with systems, then graph linear inequalities and systems of inequalities to find and interpret feasible combinations under real constraints.

  • 4 lessons
  • About 125 min
  • Quiz: 11 questions

Mathematics · Grade 9

Exponents and Exponential Growth

Learners derive the laws of integer exponents from the meaning of repeated multiplication (including zero and negative exponents), then build exponential functions y = a·b^x^ and interpret their initial value, growth or decay factor and percent rate. They contrast constant differences with constant ratios, see why exponential growth eventually overtakes any linear growth, and model compound interest, depreciation, half-life and geometric sequences.

  • 4 lessons
  • About 125 min
  • Quiz: 11 questions

Mathematics · Grade 9

Polynomial Operations and Factoring

Learners add, subtract and multiply polynomials with the distributive property and area models, then reverse multiplication by factoring: greatest common factors, trinomials (including leading coefficients other than 1) and the special forms difference of squares and perfect-square trinomials. They learn to factor completely, to see structure such as x^4^ − 81, and to check any factorization by multiplying or substituting.

  • 4 lessons
  • About 125 min
  • Quiz: 11 questions

Mathematics · Grade 9

Quadratic Functions and Equations

Learners read the vertex, axis of symmetry, intercepts and direction of a parabola from its standard, vertex and factored forms, then solve quadratic equations by factoring, square roots, completing the square and the quadratic formula, using the discriminant to predict the number of real solutions. Projectile and area models end the course, with attention to rejecting solutions that make no sense. An optional honors lesson derives the quadratic formula.

  • 5 lessons
  • About 140 min
  • Quiz: 11 questions

Mathematics · Grade 9

Data, Correlation and Model Critique

Learners summarize distributions with center, spread, shape and outliers, look for associations in two-way tables using conditional relative frequencies, and describe scatterplots with direction, form, strength and correlation. They fit and interpret linear models, judge fit with residuals, and critique claims that confuse correlation with causation, ignore lurking variables, extrapolate, or use misleading graphs.

  • 4 lessons
  • About 125 min
  • Quiz: 11 questions

Mathematics · Grade 9

An Algebra Modeling Investigation

A capstone investigation that pulls the year together. Learners help a fictional town plan its community fair: they formulate questions and assumptions, choose between linear and exponential models of attendance and advertising reach, build a quadratic revenue model to set a ticket price under a crowd constraint, and validate their models against new data before writing a recommendation with stated limitations.

  • 4 lessons
  • About 150 min
  • Quiz: 11 questions