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Math that explains itself

Interactive, step-by-step calculators for high school and college — algebra through calculus, each one built to teach, not just answer.

22 calculatorsStep-by-step solutionsGraphs & diagramsPractice problems

Algebra

4 calculators
∪Algebra

Quadratic Formula

Solve ax² + bx + c = 0 — real or complex roots, with a graph.

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╱Algebra

Slope & Line Equations

Slope, every line form, distance and midpoint from two points.

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⋔Algebra

Systems of Equations

Solve two linear equations and see where the lines cross.

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xⁿAlgebra

Exponents & Roots

Powers and roots — negative and fractional exponents too.

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Geometry

4 calculators
△Geometry

Pythagorean Theorem

Find a missing side of a right triangle, with a diagram.

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▱Geometry

Area & Perimeter

Area and perimeter for five common shapes, with diagrams.

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◧Geometry

Volume & Surface Area

Volume and surface area for six 3D solids.

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◯Geometry

Circle

Radius, diameter, circumference and area from any one.

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Trigonometry

3 calculators
∿Trigonometry

Trig Functions

All six functions, quadrant and reference angle on the unit circle.

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◺Trigonometry

Law of Sines

Solve triangles from angle–side pairs (AAS / SSA).

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△Trigonometry

Law of Cosines

Solve triangles from two sides + an angle, or all three sides.

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Statistics

4 calculators
x̄Statistics

Mean, Median & Mode

The three averages, range and spread for any list.

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σStatistics

Standard Deviation

Variance and standard deviation, sample or population.

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zStatistics

Z-Score

Standardize a value and read its percentile on the bell curve.

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CStatistics

Combinations & Permutations

Count the ways to choose or arrange items.

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Pre-Calculus

3 calculators
logPre-Calculus

Logarithms

Logs of any base, with change-of-base steps.

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ΣPre-Calculus

Sequences

Arithmetic and geometric terms and sums.

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ⁿPre-Calculus

Binomial Theorem

Expand (a + b)ⁿ with the Pascal-row pattern.

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Calculus

2 calculators
dxCalculus

Derivatives

Differentiate polynomials term by term, with the power rule.

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∫Calculus

Integrals

Integrate polynomials term by term, with + C.

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College

2 calculators
▦College

Matrix

Determinant, inverse and transpose of 2×2 and 3×3 matrices.

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iCollege

Complex Numbers

Arithmetic, modulus and argument on the complex plane.

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Formula Cheat Sheets

5 reference sheets
=Algebra

Algebra Formulas

Slope, quadratic formula, exponent rules, factoring identities, sequences and more.

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θTrigonometry

Trig Identities

Pythagorean, reciprocal, double angle, half angle — all eight families with examples.

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f′Calculus

Derivative Rules

Power, product, quotient, chain, trig, exponential and log — each with a worked example.

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μStatistics

Statistics Formulas

Mean, variance, z-score, probability rules, combinations and permutations.

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△Geometry

Geometry Formulas

Area, perimeter, volume and surface area for 2D and 3D shapes, plus angle relationships.

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