When teaching in a school in the UK, I found most of the small tools I needed online wanted my email, or displayed a lot of ads (sometimes both!)
So, I started making my own resources. They're free and work in any browser.
If you have any suggestions for new tools, let me know at hello@dandruce.co.uk.
A fullscreen exam countdown. Logs extra time and rest breaks, and stays readable from the back of the room.
A fullscreen board for halls running several papers at once - each subject shows its own normal and extra-time end times.
Countdown, stopwatch and clock in one. Digital or analogue, fullscreen, with colour warnings as time runs out.
Paste a class list and pick at random. Fair mode covers everyone before repeating, and a second tab makes random groups.
Sketch a room, drop in names and auto-generate a plan that respects keep-apart and sit-together rules. Import/export as Excel.
Build a colour-coded weekly timetable in minutes. Multiple weeks, day and week views, and a print-ready export.
Drop in a class list and run a league table and/or a knockout - great for competitions or end-of-term quizzes.
Enter raw marks and grade boundaries for a full percentage table, box plot and grade distribution. Any exam board.
A whole academic year on one page. Enter term and inset dates; bank holidays fill in and the totals print to a single page.
Sine, cosine and tangent built off the unit circle; sec, cosec and cot; the CAST rule and the inverse functions. KS4-KS5.
Prove the identities from the unit circle, then the compound, double and R sin/cos formulas, plus small-angle approximations. KS4-KS5.
The sine rule, cosine rule and area formula, each proved from one draggable triangle, with the ambiguous case. KS4-KS5.
A one-page map of every A-level and Further Maths distribution: shape, when to use it, mean, variance and formula.
Explore X ~ B(n, p). Reshape the bars with n and p, find P(X = k), cumulative and range probabilities, and the conditions.
Explore the normal curve: translation and stretch with the mean and sd, the 68-95-99.7 rule, a probability calculator and Z-scores.
Sample spaces, cards, spinners, probability trees and Venn diagrams - interactive tools for teaching GCSE probability.
Drag numbers into sets, learn the operations by shading, paint Venn diagrams and read conditional probability. Complex-numbers toggle.
Type your own numbers and watch every step: dimensions, addition, multiplication, the determinant and inverse (2x2 and 3x3). KS4-KS5.
See what a 2x2 matrix does to the unit square: rotations, reflections, stretches, shears, and the invariant points and lines. KS4-KS5.
The whole A-level topic, interactive: the gradient of a chord, the power rule, gradient functions, sketching derivatives, tangents and normals, stationary points and the full first-principles proof. KS5.
There are no ads, no accounts and no premium tier. If something here saved you time, a one-off tip on Ko-fi keeps the domain renewed and the next tool moving.