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
← Back

Addition and subtraction strategies

Mathematics · Addition & Subtraction · procedural

Use counting on and counting back as strategies for addition and subtraction

What mastery looks like

  • Add 8 + 3 by starting at 8 and counting on 3 (9, 10, 11)
  • Subtract 12 − 3 by counting back 3 from 12 (11, 10, 9)
  • Explain that counting on is a way to add

Check your understanding

If Addition and subtraction strategies needs to work out '8 + 5', can they start from 8 and count up five more — rather than starting from 1 every time?