Dan Druce · Portfolio

Teaching Tools

Overview

While teaching, I kept reaching for small classroom tools online but most of them wanted personal details or had buried the feature behind ads, sometimes even both. I couldn't stand projecting advertising onto my whiteboard, so, I started building my own. tools.dandruce.co.uk is the result: a growing collection of free, browser-based tools I use day to day to enhance my own teaching. There is nothing to sign up for, no adverts, and everything runs entirely in the browser.

The screenshot below is the Normal Approximation tool from the Binomial Distribution page. Students can drag the number of trials and probability of success and watch the normal curve settle over the binomial bars, with the validity conditions and summary statistics updating live - the kind of visual intuition that is hard to convey on a whiteboard and where a digital resource excels.

Normal Approximation tool: a normal curve overlaid on binomial bars, with parameter sliders, validity checks, and mean, variance and standard deviation cards

What I Built

The tools fall into two broad groups: interactive topic explorers that I project in lessons, and practical utilities that save time around the classroom. Each one is designed to do a single job well and load instantly. They include:

  • Topic explorers - interactive visualisers for probability distributions, calculus (differentiation and integration), trigonometry and non-right-angled trig, matrices, transformations, set notation and GCSE probability, built to give students intuition for concepts that are hard to do by hand effectively.
  • Exam and timing tools - fullscreen exam-condition clocks, a multi-paper exam board that tracks separate normal and extra-time end times, and a flexible classroom timer with countdown, stopwatch and clock modes.
  • Classroom utilities - a seating-plan builder, a random student picker, a mark calculator, a timetable builder, a dynamic calendar and a tournament bracket maker.

Every tool is designed to be readable from the back of the room and to work on whatever browser a school uses, with no installation or account required.

Sharing & Suggestions

I originally made these purely for myself, but once they were working it made sense to share them so other teachers would not have to build the same thing from scratch. I publish them on TES and other teaching communities for free and ad-free.

I also take requests. When teachers suggest a tool, they wish existed, I build it and add it to the collection - so the site keeps growing based on what is genuinely useful in real classrooms.