Te reo Māori terms
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Master Teaching Guide coverage for this objective.
Resources
- CorbettMaths on BoundsQuestions PDF · Answers
- CorbettMaths on Error IntervalsQuestions PDF · Answers
- Beta: Various from chapters 22-24 (Limits of Accuracy and error propagation)
Terminology
- Measurement tolerance
- Upper bound
- Lower bound
- Central estimate
- Nearest unit
- Error propagation
- Worst case
Task goals
- Apply the convention that a measurement "given to the nearest X" has an implied tolerance of plus-or-minus half of X, and state the resulting interval of possible true values.
- Calculate the central (best) estimate of a measurement-based quantity -- area, perimeter, or volume -- from the given measurements.
- Recompute the same calculation using the most extreme plausible combination of inputs to find the minimum possible final answer.
- Recompute the same calculation using the most extreme plausible combination of inputs to find the maximum possible final answer.
- Correctly identify, for a given formula's structure, which extreme (upper or lower bound) of EACH input genuinely produces the overall minimum or maximum -- recognising that for a calculation containing a subtraction step, the minimum of the total can require the MAXIMUM of the subtracted piece, not a blind "all lower bounds" rule.
- Propagate two or more compounding measurement tolerances (from different measured quantities, potentially with different stated precisions) through a multi-step calculation.
- Use a calculated minimum or maximum bound as an input to a further material-quantity, discrete-purchase, or cost calculation.
- Determine whether a calculated uncertainty range changes a real-world decision (a discrete-purchase quantity, a budget compliance check, or a minimum-size requirement), and justify the conclusion with the actual minimum/maximum figures.
- Recognise that an uncertainty range sometimes does NOT change the real-world decision, and explain why the central estimate alone was already a safe enough basis for that particular decision.
- Communicate a written discussion of measurement uncertainty's real-world significance, referencing the specific minimum/maximum values found.
Key skills
- Apply the nearest x implies tolerance of half x convention
- Calculate the central estimate of a measurement based quantity
- Recompute a calculation at its extreme inputs to find the minimum possible answer
- Recompute a calculation at its extreme inputs to find the maximum possible answer
- Correctly choose which extreme of each input drives the overall minimum or maximum
- Recognise that a subtraction step can reverse the naive all lower bounds rule
- Propagate two or more compounding tolerances through a multi step calculation
- Use a minimum or maximum bound as an input to a further purchase or cost calculation
- Determine whether an uncertainty range changes a real world decision
- Explain why an uncertainty range sometimes does not change a decision
- Communicate a written discussion of measurement uncertainty referencing actual figures
Quick stats
- 81 total questions
- 3 difficulty levels
- Answers included
For teachers
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