Pre-Algebra
The building blocks — pick a topic below.
The same order-of-operations engine as Calculate.
Fraction arithmetic, kept exact — no rounding unless you ask for the decimal.
Long addition, subtraction, multiplication, or division, shown the way it's worked out on paper.
Turn a fraction into a decimal, with repeating digits marked — found the same way long division finds them.
Expand a whole-number power into repeated multiplication, or pull the largest perfect-square factor out of a radical.
Solve a proportion for its missing term by cross-multiplying.
Write it in plain words — 15% of 200, 25 is what % of 80, or 40 is 20% of what.
The remainder after division — write it as a mod b.
Plot one or more numbers — comma-separated, fractions and negatives welcome.
Calculate
Ask anything in maths — type an expression or a plain-English question. The answer comes back as a set of panels: the result, other forms, a plot, roots, derivative, integral, number facts and a step-by-step solution, just like a computational knowledge engine.
Solve
Enter an equation in one variable. Linear and quadratic equations get the full closed-form derivation (a quadratic can also be solved by graphing); cubic, quartic and higher polynomials are solved by the graphing method, with the answers marked on the graph, or numerically; other equations get all real roots found numerically across −100 to 100.
Logarithms
Evaluate a log expression — log(x) is natural log, log(x, b) is log base b — with the change-of-base steps shown. Write an equation instead (log(x,2) = 5 or 3^x = 81) to solve for the unknown.
Simple/Compound Interest
Interest that only ever grows on the original principal, never on interest already earned.
Interest that's added back to the principal each compounding period, so later interest is earned on top of it too.
Derivatives
Differentiates with respect to the variable of your choice, simplifies the result, and locates the critical points where the derivative is zero.
Multivariable Calculus
Write a function of two or more variables. Every variable found gets differentiated in turn, treating the others as constants — plus the gradient, the second-order and mixed partials for two variables, and, if you give a point and direction, the directional derivative there.
Descriptive Statistics
Eighteen focused calculators. Seventeen of them — everything but Probability — share one list of numbers below; switch tabs to see that same list through a different lens.
Graph
Plot one curve per line — a bare expression in x, a y = … or x = … form, or a full equation in x and y such as a circle or line. Scroll to zoom, drag to pan, hover to read off coordinates, and click directly on a curve to trace its exact value there.
Scan a Photo
Upload a photo of a problem and the board reads the text off it, right in your browser — nothing is uploaded anywhere. Printed text comes through far more reliably than handwriting, so always check the reading before solving.
Voice Input
Speak a problem instead of typing it — say things like "two x plus five equals eleven" or "square root of one hundred forty four". Depending on your browser, the audio may be sent to its own speech-recognition service to be transcribed (this page never sees or stores it) — this is the one input method here that isn't purely local.
Check My Work
Write the original problem, then your own working, one line per row. Every line is checked against the one before it for whether it's a valid algebraic step — where it breaks, the board takes its best guess at the kind of slip and coaches rather than just marking it wrong.
Limits
Estimated numerically — the board samples the function extremely close to the point from both sides, rather than deriving a symbolic result — so it works on anything, including forms like sin(x)/x that would otherwise divide by zero.
Integrals
Finds an antiderivative using the power rule, basic trig/exponential/logarithmic forms, and linear substitution — not integration by parts. Add bounds for a definite integral, evaluated numerically either way as a cross-check.
A double integral over a rectangular region, computed numerically (nested Simpson's rule) — no symbolic form, just the value.
A triple integral over a rectangular box, computed numerically the same way as the double integral.
A contour integral around a circle in the complex plane, computed numerically by parametrizing z = center + r·eiθ. Write the function in terms of z, using i for the imaginary unit (e.g. 1/z, or 1/(z - 2*i)).
Derivative Applications
Enter a function of one variable for its critical points (classified as a local max, local min, or neither), where concavity switches, and — if you give a point — the tangent line there.
Integral Applications
The area between a curve and the x-axis, over [a, b] — using |f(x)|, so regions below the axis count as positive area too.
The area trapped between two curves f(x) and g(x), over [a, b].
The volume swept out by rotating f(x) around the x-axis, over [a, b] (the disk method).
Integral Approximation
Approximate a definite integral with a fixed number of subintervals — a way to see how Riemann sums, the Trapezoidal Rule, and Simpson's Rule converge toward the true value.
Series
Write the general term as a function of n, then a starting and ending index — use Infinity for the end to sum (or test the convergence of) an infinite series.
ODE
Solve dy/dx = f(x, y) numerically from an initial condition, using 4th-order Runge–Kutta — this works even when there's no closed-form solution.
Laplace Transform
Write f(t). Common forms — constants, powers of t, exponentials, sin/cos, and simple products of these — are matched against a table of known transforms; anything else falls back to a numeric evaluation of L{f}(s) = ∫₀^∞ f(t)e−st dt at the s-value you give.
Taylor/Maclaurin Series
Expands f(x) as a polynomial around a center point — center 0 gives the Maclaurin series. Each coefficient comes from differentiating repeatedly and evaluating at the center.
Fourier Series
Approximates a function that repeats every 2L with a sum of sines and cosines — the coefficients are found by numeric integration over one period.
Fourier Transform
Evaluates F(ω) = ∫f(t)e−iωt dt numerically, over the finite range you give in place of −∞ to ∞ — wide bounds approximate the true (improper) transform for functions that decay away from the origin.
Systems
Enter one linear equation per line — as many unknowns as equations, up to four. Solved by Gaussian elimination (LU decomposition).
Shapes & Solids
Pick a shape, fill in its measurements, and get area/perimeter (2D) or volume/surface area (3D) with the steps shown.
Conics
A circle centered at (h, k) with radius r.
An ellipse centered at (h, k) with horizontal semi-axis a and vertical semi-axis b.
A parabola with vertex (h, k) and distance p from vertex to focus (p's sign sets the opening direction).
A hyperbola centered at (h, k) with semi-axes a and b.
Unit Conversion
Pick a category, then type into either box — the other side updates instantly, along with the formula behind it.
Triangle Solver
Fill in exactly three measurements — at least one side — and leave the rest blank. Angle A is opposite side a, B opposite b, C opposite c.
A quick-reference sheet of the standard identities. To evaluate an actual trig expression, use Calculate — sin, cos, tan and their inverse and hyperbolic forms all work there.
Pythagorean
Reciprocal & Quotient
Co-function (degrees)
Sum & Difference
Double Angle
Half Angle
Triangles
Evaluate Trig Functions
Enter an angle (in degrees, or in radians such as pi/6) and get all six trig function values at once. Every value is given exactly, as a whole number, a fraction or a radical, wherever an exact value exists, and the working is shown.
Inverse Trig Functions
Find the angle whose trig function equals a given value (the principal value).
Basic Calculator
A plain button calculator — add, subtract, multiply, divide. Great for quick everyday sums.
Scientific Calculator
Everything the basic calculator has, plus trig, logs, powers, roots, and constants.
Percent, Decimal & Fraction
Type into any one box — the other two update instantly, kept exact wherever possible. Covers converting between percent, decimal, and fraction in either direction.
AI Tutor
Ask a maths question in plain English and get a step-by-step answer from Claude. No sign-in or key needed.
Use my own Anthropic API key instead (optional)
AI answers can contain mistakes, so check important work with your teacher. Report a problem with an answer.
Coordinate Geometry
The straight-line distance between two points.
The point exactly halfway between two points.
The steepness of the line through two points.
The point that divides a segment in a given ratio m∶n, measured from the first point toward the second.
The area of a triangle from its three vertices — also flags when the points are collinear (area = 0).
Parallel & Perpendicular Lines
Given a line's slope and a point not on it, find the line through that point parallel to it, and the line through that point perpendicular to it.
Given the slopes of two lines, determine whether they're parallel, perpendicular, or neither.
Probability & Combinatorics
The number of ways to arrange r items out of n, where order matters.
The number of ways to choose r items out of n, where order doesn't matter.