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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.

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Computing
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Ratio (age 10+)

Mathematics · Multiplication & Division · procedural

Perform mental calculations including with mixed operations and large numbers, using strategies such as partitioning, compensation, and derived facts

What mastery looks like

  • Mentally compute 45 × 8 by partitioning into 40 × 8 + 5 × 8
  • Use known facts to derive 6.5 × 4 mentally
  • Solve a multi-operation mental calculation such as 250 × 3 + 500 and explain the strategy used

Check your understanding

Can Ratio (age 10+) work out a mixed calculation like '(200 × 6) + 350 − 75' entirely in their head — keeping track of each step without writing anything down?

Prerequisites

Required first

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