Hand-authored, step-by-step lessons across grades 4 through Algebra II. Free to read. Subscribers get a 10-question diagnostic on every skill — score, hints, worked solutions, parent visibility.
Read, write, compare, and round numbers up to a million.
Standard algorithms, word problems, and estimation.
Single-digit × four-digit and two-digit × two-digit.
Long division up to four-digit by one-digit, with word problems.
Prime, composite, factor pairs, and number patterns.
Equivalent fractions and comparing fractions with different denominators.
Operating on fractions with like denominators and by whole numbers.
Tenths and hundredths — notation, comparison, decimal-fraction equivalence.
Unit conversion, perimeter, area, and reading line plots.
Lines, angles, classification of triangles and quadrilaterals.
Decimal place value, comparison, and rounding to thousandths.
Multiplying and dividing by powers of 10, plus standard whole-number algorithms.
Add, subtract, multiply, and divide decimals to hundredths.
Unlike denominators, mixed numbers, and word problems.
Fraction × fraction, fraction × whole, and dividing whole numbers by unit fractions.
Plotting ordered pairs in the first quadrant and reading scale.
Order of operations, writing expressions, and analyzing patterns.
Converting between units within the same system.
Volume of right rectangular prisms via unit cubes and the formula.
Hierarchy of quadrilaterals and properties of triangles.
Reading and constructing line plots with fractional measurements.
Ratio language, rates, and unit-rate problems.
Percent of a quantity, finding the whole, and percent change.
Fluent fraction division, decimal operations, and divisibility.
Integers in context, absolute value, and the four-quadrant plane.
Writing, reading, and evaluating algebraic expressions.
One-step equations and inequality reasoning.
Area of triangles, quadrilaterals, and composite shapes.
Volume of prisms with fractional edges and surface area via nets.
Statistical questions, measures of center, and data displays.
Identifying proportional relationships, constants of proportionality, scale.
Markup, discount, tax, tip, simple interest, and percent change.
Adding, subtracting, multiplying, and dividing signed numbers.
Combining like terms, distribution, and equivalent expressions.
Two-step equations and one-step inequalities in real-world contexts.
Angle relationships, triangles, and scale drawings.
Circumference, area of a circle, and composite figures.
Surface area and volume of prisms; cross-sections.
Theoretical vs experimental probability, sample spaces, and inference.
Integer exponents, scientific notation, and rational vs irrational.
Multi-step linear equations and equations with variables on both sides.
Slope, y-intercept, slope-intercept form, and graphing.
Function definition, evaluating, and comparing linear vs nonlinear.
Solving systems by graphing, substitution, and elimination.
Translations, reflections, rotations, dilations, and congruence.
Pythagorean theorem and its converse in 2D and 3D.
Volume formulas for cones, cylinders, and spheres applied to word problems.
Scatter plots, lines of best fit, and two-way frequency tables.
Properties of real numbers, combining like terms, and distribution.
Solving linear equations, inequalities, and systems with one variable.
Slope, intercepts, slope-intercept and point-slope forms.
Solving 2-variable systems by substitution, elimination, and graphing.
Function notation, domain and range, and reading graphs.
Arithmetic and geometric sequences, recursive vs explicit forms.
Exponent rules, exponential growth and decay.
Adding, subtracting, and multiplying polynomial expressions.
Factoring trinomials, difference of squares, and factor by grouping.
Solving by factoring, square roots, completing the square, and the formula.
Vertex, axis, intercepts, and graphing parabolas.
Center and spread, two-way tables, and bivariate data.
Postulates, segment and angle relationships, and the building blocks of proofs.
Translations, reflections, rotations, and dilations as functions on the plane.
SSS, SAS, ASA, AAS, HL — and how to use them in a proof.
AA similarity, scale factors, and applications.
Pythagorean theorem, special right triangles, and SOHCAHTOA.
Properties of parallelograms, trapezoids, and regular polygons.
Central and inscribed angles, arc length, sector area, and equations of circles.
Distance, midpoint, slope, and proving figures on the plane.
Surface area and volume of prisms, pyramids, cylinders, cones, and spheres.
Adding, subtracting, multiplying, and dividing polynomials.
End behavior, zeros, factor theorem, and graphs of higher-degree polynomials.
Imaginary unit, complex arithmetic, and complex conjugates.
Simplifying radicals, rational exponents, and solving radical equations.
Simplifying, operating on, and solving equations with rational expressions.
Exponential growth/decay, the number e, log laws, and solving exp/log equations.
Unit circle, six trig functions, and their graphs and transformations.
Pythagorean, sum-difference, double-angle, and proving identities.
Circles, ellipses, parabolas, and hyperbolas in standard form.
Arithmetic and geometric series, sigma notation, and infinite geometric series.
Conditional probability, independence, and the rules of probability.
Sample surveys, experiments, observational studies, and inference.
Each diagnostic pulls 10 calibrated questions from our bank, scored with hints and worked solutions. Plus daily SMS practice and weekly parent reports.