Maths · KS3 Y8 · Probability

Probability of single events

m18Free1:39Heddy Score 2 of 7, below the standard

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What you need to know

  • Probability runs from 0 (impossible) to 1 (certain).
  • With equally likely outcomes, probability is favourable outcomes over total outcomes.
  • The probability something does not happen is 1 minus the probability it does.

In this clip

3:18–4:09Estimating before calculatingm32
4:09–4:50Prime factorisationm26
8:36–9:42Fractions of amountsm4
9:42–13:12Standard form: large numbersm46
13:12–15:03Place value & orderingm1
15:03–18:29Fractions ↔ decimals ↔ %m12
18:29–20:34Negative numbersm2
20:34–22:23Simplifying expressionsm6
22:23–23:25Substituting into expressionsm56
23:25–24:15Inequalities on a number linem72
24:15–24:53Solving linear inequalitiesm73
24:53–30:03Solving quadratics by factorisingmh8
30:03–33:54Graphs of quadraticsm85
33:54–35:24nth term of linear sequencesm70
35:24–37:50Metric unit conversionsm91
37:50–40:14Percentages of amountsm38
40:14–46:10Percentage increase & decreasem39
46:10–49:03Ratio notationm7
49:03–50:40The unitary methodm90
50:40–58:16Speed, distance, timem96
58:16–60:35Density as a ratem97
60:35–62:07Reflecting shapesm120
62:07–67:10Plans & elevationsm146
67:10–69:41Angles in polygonsm16
69:41–70:42Volume of cuboidsm117
70:42–71:27Volume of cylindersm140
71:27–73:24Exact trigonometric valuesgcse-math-g21
73:24–74:45Pictograms & their keysm164
74:45–79:19Bar chartsm163
80:33–82:12Probability of single eventsm18
82:12–84:20Frequency treesm159
Also coversAdding fractions, unlike denominatorsm34
Also coversCalculating in standard formm48
Also coversDirect proportion y = kxm102
Heddy Score2/7, Below the standard
  • 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 · not judged yet. 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
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How the Heddy Score works

Why we picked it

Topic-by-topic Foundation revision built around the May 2023 Paper 1; many chapters are KS3-level skills, useful for Year 9–11 Foundation students.

The GCSE Maths Tutor on YouTubechecked 2026-10-16