AI Constitution

Resources · Learning tool

Education Concept Tracker

A prerequisite knowledge graph of 1590 learning concepts across 8subjects. Track what you've mastered and see exactly what you're ready to learn next — the topics whose prerequisites you've already met. Built on the Marble Open Skill Taxonomy.

Sign in to track your progress and get personalized recommendations. You can browse freely below.

Knowledge-graph map

Computing
Mastered Ready to learn LockedHover a node for its description · click to open
Computers in Everyday L…Computers in Everyday Life — frontier Identifying computers in everyday life — not just laptops but phones, tablets, smart speakers, traffic lights, washing machines; what makes something a computerReal-World RobotsReal-World Robots — locked What a robot really is — not the sci-fi version; robots in factories, robot vacuum cleaners, robot arms in surgery; that robots follow instructions given by peopleSmart Versus Not-Smart…Smart Versus Not-Smart Devices — locked Sorting objects into 'smart' (can sense and respond) and 'not smart' (just sits there); a toaster vs a smart speaker; introduction to the idea that some machines can sense and respond to the worldStep-by-Step Instructio…Step-by-Step Instructions — locked Step-by-step instructions for everyday tasks (making a sandwich, brushing teeth); that if instructions are wrong or missing, things go wrong; computers follow instructions exactly
← Back

Inverse: addition undoes subtraction

Mathematics · Addition & Subtraction · conceptual

Recognise and use the inverse relationship between addition and subtraction to check calculations and solve missing-number problems

Sign in to track this

What mastery looks like

  • Check 15 + 7 = 22 by calculating 22 − 7 = 15
  • Use the inverse to solve: □ + 9 = 14, so □ = 14 − 9 = 5
  • Explain that addition and subtraction 'undo' each other

Check your understanding

If Inverse: addition undoes subtraction works out 13 + 5 = 18, can they immediately use that to say '18 − 5 = 13' — without having to work the subtraction out all over again?

Prerequisites

Required first

Unlocks (1 directly)