Likelihood Language
Use probability language to describe and compare the likelihood of everyday events using words such as certain, likely, even chance, unlikely, impossible
What a learner can do afterwards
- Place five everyday events, such as rolling 8 on a normal die, picking 1 green ball from 5, a fair coin landing tails, picking red from 7 red and 3 blue balls, and picking red from a bag containing only red balls, from impossible to certain.
- Use 'likely', 'unlikely', 'certain', 'impossible', and 'even chance' correctly to describe different events
- Explain why pulling a red ball from a bag of mostly red balls is 'likely' but not 'certain'
1 · Read
Some events always happen, some never happen, and others may happen. A normal six-sided die always shows 1, 2, 3, 4, 5, or 6. Getting one of those numbers is certain. Getting 7 is impossible. Use likely, unlikely, and even chance for events between those ends.
Mia has a bag with 8 red balls and 2 blue balls. She reaches in without looking. Pulling a red ball is likely, because most of the balls are red. But it is not certain, because the blue balls are still in there too.
A fair coin can land heads or tails. Neither side has a bigger chance, so heads is an even chance. A bag with 3 red and 3 yellow balls is the same: half the balls are red, so red is an even chance. Likely needs more than half. On a fair die, a number above 4 can come up two ways: 5 or 6. Rolling a 1 has one way, so a number above 4 is more likely than a 1.
Try placing five events from least likely to most likely. Rolling 8 on a normal die is impossible. Picking 1 green ball from a bag of 1 green and 4 yellow balls is unlikely. A fair coin landing tails is an even chance. Picking red from a bag with 7 red and 3 blue balls is likely. Picking red from a bag containing only red balls is certain.
Impossible never happens, certain always happens, and unlikely, even chance, and likely sit in between them.
Two short readings are adapted from Khan Academy articles, 'Key ideas: What is probability?' and 'Probability: the basics'; their terms are unknown. Linked YouTube videos: 'Basic Probability | Is It Equal, Likely, Unlikely, Certain, or Impossible?' by Turtlediary and 'Calculating Probability as a Fraction' by EasyTeaching; the videos belong to their channels, and only the link records were curated for os-taxonomy. The reading 'Likely is not certain', the nine extra practice questions and the six flashcards were written for os-taxonomy.
2 · Watch
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