Maths · KS3 Y7 · Number

HCF & LCM

HCF & LCMFree6:48Heddy Score 3 of 7, below the standard
Next clip

What you need to know

  • A multiple of a number comes from multiplying it by a whole number, like counting in steps.
  • To find the LCM, list multiples of each number until you reach the first one they share.
  • The LCM of 4 and 10 is 20, and the LCM of 9 and 6 is 18.
  • For three numbers, such as 12, 4 and 8, keep extending the lists until one multiple appears in all of them (24).

In this clip

Runs 6:48, from 0:05 to 6:53 of the full video.

Heddy Score3/7, Below the standard
See the seven stars
  • Trusted source · passed. The creator's own upload, live and playable here.
  • On the map · not judged yet. A teacher watched it: it mainly teaches this map topic.
  • Spec-true · not judged yet. Accurate, and right for the current UK specification.
  • Focused · passed. One idea, short enough to watch in one go.
  • Accessible · passed. Good captions, clear sound and pictures.
  • Safe for children · not judged yet. Right for 11 to 16 year olds, with no sales pitch.
  • Proven · not judged yet. Earned from our students: they learn from it, find it helpful and watch it to the end.
★ passed · ☆ pending · ✕ failed
Our students

Not enough students yet

Our own students' answers. These are what move ★7 Proven.
On YouTube

781K views · 6.23K likes · Math with Mr. J 2.03M subscribers

As reported by YouTube on 2026-11-02. Not part of the Heddy Score.
How the Heddy Score works

Why we picked it

A clear listing method for the lowest common multiple, including a three-number example.

Math with Mr. J on YouTubechecked 2026-10-22

Plays from youtube-nocookie.com. No YouTube cookies until you press play.