Maths · KS3 Y9 · Algebra

Geometric sequences

Geometric sequencesFree3:24Heddy Score 3 of 7, below the standard
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What you need to know

  • A geometric sequence multiplies by the same number, the common ratio, to get from one term to the next.
  • In 3, 6, 12, 24, 48 the common ratio is 2, so adding 3 only works for the first step.
  • The nth term of a geometric sequence is the first term multiplied by the ratio to the power n − 1.
  • Work out the power before multiplying by the first term.
  • To find a term's position, set the formula equal to the value and solve for n.
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

610K views · 4.53K likes · Kevinmathscience 1.13M subscribers

As reported by YouTube on 2026-11-01. Not part of the Heddy Score.
How the Heddy Score works

Why we picked it

Shows clearly why a geometric sequence multiplies rather than adds and how to find any term from the first term and the ratio.

Kevinmathscience on YouTubechecked 2026-10-22

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