Mathematics lessons where students get their hands on the graph: drag a point, stretch a curve, roll a die a thousand times and check the sums. As with the physics lessons, each lesson is a single page that opens on a phone or a computer, with nothing to install.
Sets and their operations, intervals on the number line, from the naturals to the reals, scientific notation and orders of magnitude.
What makes a rule a function, domain and range, reading graphs, rate of change, piecewise functions, transformations, composition and inverses.
Constant rate of change, proportionality, straight lines that model tariffs and consumption, and linear inequalities.
The parabola, the vertex, the roots and the sign, and maximum and minimum problems.
Growth and decay, half-life, the properties of the logarithm and logarithmic scales: pH, decibels and Richter.
See also: Modern Physics, half-life
Arithmetic and geometric progressions as functions of the natural numbers, the general term, sums and the sum of an infinite geometric progression.
Percentages, successive increases and discounts, simple and compound interest, and what lies inside a loan.
Sine, cosine and tangent in the right-angled triangle, the laws of sines and cosines, the unit circle and periodic functions.
See also: Circular Motion, sine and cosine
Similarity, Pythagoras, areas of plane figures, isometries and homotheties.
Prisms, pyramids, cylinder, cone and sphere, nets, areas and volumes.
Points and distances in the Cartesian plane, the equation of the line and of the circle.
Matrices and their operations, 2 × 2 and 3 × 3 systems and what they mean in geometry.
The multiplication principle, permutations, arrangements and combinations.
Sample space and events, conditional probability, independence and simulations with many trials.
Charts, mean, median and mode, standard deviation and how a sample represents, or fails to represent, a population.
Flowcharts, pseudocode, decisions and loops, and how to describe a mathematical procedure step by step.
Each step will have a drawing that responds to the controls: a point dragged along a curve, a line that rotates, a die rolled a thousand times. The numbers on screen use the same formulas as the text.
Questions that ask you to try things: ‘double the slope’, ‘move the vertex to the left’, ‘swap the function and see what happens to the domain’.
10 per step (4 basic, 4 intermediate and 2 challenges), with the worked solution hidden until you click.
At the end, challenges that mix the steps, five ENEM-style questions (Brazil's national secondary-school exam) and a sheet with every formula in the lesson.