Interactive IB mathematics. Drag the points until the model breaks, answer a question and be told which specific mistake you made, not just that you made one.
Free. No sign-in. Nothing you type is stored or sent anywhere.
Eight points, almost a perfect line.
Most maths sites show you a worked answer. These pages watch what you do and tell you what went wrong with it.
Not "incorrect, try again". Type 42 instead of 48 and it tells you that you added one interquartile range rather than one and a half.
Drag one point and watch a correlation of 0.989 collapse. Fit a cubic and watch it predict the coffee freezes. Things you cannot do on paper.
Every page ends with what examiners actually give marks for, which is usually not the calculation you spent the time on.
Every page is used with a real class before anyone else sees it. That is the only way to know which wrong answers to expect.
The four sub-topics most courses hurry past, plus the two only Higher Level takes. Shared between Applications and Interpretation and Analysis and Approaches, SL and HL.
4.1 Where the data came from Sampling, bias, and what an outlier does to the mean. 4.2 The picture is a choice Histograms, cumulative frequency and box plots. 4.3 Where it sits, and how far it spreads Averages, standard deviation, and what adding or multiplying does. 4.4 Correlation and regression Pearson's r, the regression line, and when a prediction stops being allowed. 4.13 When a line is the wrong shapeHL Fitting curves, and why a better number is not a better model. 4.12 Asking a question that does not answer itselfHL Survey design, and the difference between reliable and valid.Where the derivative comes from and what its sign tells you. All eight Standard Level sub-topics plus all ten Higher Level ones, in teaching order so the differentiation runs together. 5.1 to 5.5 are shared with Analysis and Approaches.
5.1 Limits and the derivative Watch a chord collapse into a tangent while the gradient closes on 2. 5.2 Reading the derivative f and f′ move together, and a zero gradient turns out not to mean a maximum. 5.3 Differentiating powers of x The power rule, checked against a real chord so it is not a recipe from nowhere. 5.4 Tangents and normals The usual slip draws a tangent that touches the curve nowhere at all. 5.6 Stationary points Drag the end of the interval and watch the highest point jump to the edge. 5.7 Optimisation in context Cut the corners off a sheet and watch the box fight itself for volume. 5.5 Integration and area The region fills as you slide the limit, with the integral written above it. 5.8 The trapezoidal rule Add strips and watch which side of the curve every chord sits on.All eight sub-topics of Topic 5, the complete Standard Level calculus course.
Higher Level too: ten more sub-topics, 5.9 to 5.18, including kinematics, volumes of revolution, slope fields, Euler’s method and phase portraits. See the Higher Level list.
Analysis and Approaches has its own Topic 5, all nineteen sub-topics from the first limit to Maclaurin series. See AA Topic 5.
Written guides on every part of the internal assessment, free and with nothing to sign up to.
Personal engagement, the aim, criterion B, reflection, choosing a topic that does not cap your grade, and where the line sits on using AI.
Read the guidesWork through what each criterion is actually looking for, before you hand it in rather than after.
Open the checkerThe guides and the checker are free and always will be. If you want me on your actual draft, that is the one thing I charge for.
Send me what you have. Within 24 hours I tell you in writing whether it can score and the first thing to fix.
Send it to meWrite it, or any part of it. The exploration is your work and it is signed as your work. What I do is make sure the thing you write is actually markable, which is a different job and the one nobody does for you.
Every page here has a teacher side: the answers, what each wrong answer reveals about a student's thinking, where the marks separate, and timings for the hour.
All of it is free to use with your classes, with no arrangement and no account. If you want the marking, the per-student questions and the view of which question your class got wrong, that is what a department licence is for.