Demystifying - HCF and LCM review

Drills

Finding the HCF and LCM of two or three numbers from prime factors, and choosing which a problem needs — past the two-number KS3 drill.

Author note — to cover
  • Fluency — HCF and LCM from given index-form factorisations of numbers past 100, with shared and separate prime factors presented as text lists (the structure the Venn diagram shows, without generated graphics); larger numbers than the KS3 drill (4 questions).
  • Harder cases — three numbers, and the smallest possible number with both its HCF and LCM with another stated, pinned so the generated answer is unique (4 questions).
  • Worded — bus, tile and gear problems where deciding between HCF and LCM is the mark (4 questions).

The test

—coming soon—

Where to go next

This mixed review uses the methods from these learning pages: