Complementary events
Understand and apply the rule that probabilities of all mutually exclusive outcomes sum to one; use this to find the probability of a complementary event (P(not A) = 1 − P(A))
Teaching approaches
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1 approach
If a spinner has three sections and one has a probability of 0.4 and another has 0.35, can your child work out the probability of landing on the third section without being told?
Understand and apply the rule that probabilities of all mutually exclusive outcomes sum to one; use this to find the probability of a complementary event (P(not A) = 1 − P(A))
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Check understanding
- Verify that probabilities of all outcomes listed for a spinner sum to 1
- Calculate the probability of NOT rolling a 6 as 1 − 1/6 = 5/6
- Identify an error in a probability distribution where the values do not sum to 1
“If a spinner has three sections and one has a probability of 0.4 and another has 0.35, can your child work out the probability of landing on the third section without being told?”
Curriculum record
- Type
- Conceptual
- Subject
- Mathematics
- Domain
- Probability
- Age range
- Ages 11–13
Standards