Maths

Two ways in: drill the basics until they're automatic, and see the harder ideas come alive.

New here? Start with the Arithmetic Trainer — a simple, fun way to help your child learn the times tables by heart. For high-schoolers, the tools below climb the curriculum from Grade 9 straight lines up to first-year calculus and statistics — grab the maths and drag it. Free, on any phone, nothing to install.

Number & arithmetic

Arithmetic Trainer

Times tables & more

Multiplication, addition, subtraction, division and powers of 2 — a learn tab to memorise, flashcards to self-test, and quizzes on one number or a mix.

Start practising →

Algebra & functions

Lines · parabolas · exp/log · polynomials

Six demos, from the straight line y = mx + b and linear systems up through transforming parent graphs, quadratics, exponentials, sequences and rational functions. The backbone of high-school algebra, made draggable.

Open the demos →

Trigonometry

Trigonometry Playground

Sine, cosine & tangent

Drag-the-angle demos for sin, cos and tan, where sine waves come from, the sine & cosine rules, radians and the key identities. Aimed at teens around 13+.

Explore the demos →

Calculus

Grade 12 · first-year

Limits · derivatives · integrals

Sneak up on a limit, watch a secant become the tangent and its slope become the derivative, then slice an area into rectangles and watch Riemann sums settle on the integral. The whole on-ramp, made visible.

Open the demos →

Vectors

Vectors & the Dot Product

u · v = |u||v| cos θ

Drag two arrows and watch the dot product, the angle between them and the projection (the "shadow") update live. Why the sign alone tells you acute, obtuse or perpendicular.

Open the demo →

Linear algebra

Matrices · complex plane · cross product

Where maths turns from numbers into space. Drag î and ĵ to watch a 2×2 matrix bend the whole plane (and the determinant become an area), see complex multiplication as a rotation, and spin a 3D cross product out of a parallelogram.

Open the demos →

Statistics & data

Probability Sandbox

Tree diagrams, live

Bend the branches of a probability tree and watch total probability and Bayes' rule recompute — then roll 1,000 virtual dice and see the theory come true. Includes the famous medical-test surprise.

Open the demo →

Data & the Normal Curve

Mean, spread & the bell

Drag a data set together and watch the mean, median, mode, range and standard deviation react — then see the 68–95–99.7 bell curve appear. Why the mean chases an outlier and the median holds.

Open the demo →

Grade 12 · first-year

Line of Best Fit

Regression & correlation

Drag a cloud of points and find the least-squares line that fits them best, with the residuals it minimises — then measure the strength of the link with the correlation r and r².

Open the demo →

University & beyond

Build waves · epicycles

The idea behind the Fourier transform, shown as geometry instead of integrals: stack sine waves to make any shape, then watch spinning circles draw it. First-year university level, no calculus needed for the idea.

See it move →

Guides

Divisible by 2, 3 or 5?

Quick number tricks

Spot whether a number divides evenly without doing the division — with worked examples, tables, and a simple proof of why the digit trick for 3 actually works.

Read the guide →