Students need to be able to read and interpret answers to check that they are appropriate for a given problem. This requires
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reading the original problem to determine the type of answer expected
- checking that the answer is appropriate for the given problem.
For example:
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the length of the hypotenuse of a triangle in centimetres
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the age of a child in years
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a quadratic function
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the probability of rain occurring on two consecutive days
Note: This skill is also relevant for tests with multiple choice options as students need to determine whether each option is reasonable.
Understanding this strategy
To model this strategy, teachers could use a multiple-choice problem where students are provided with a worded problem and options for the answers.
The options could include a range of possibilities where the answer might not be appropriate or where insufficient information is given, for example, units are missing, a scale factor is not used or an intermediate result is given as the answer (i.e. the given problem is not answered).
Students identify words in the question that give clues about the type of answer expected. They can then discuss which of the multiple-choice answers are reasonable and how they make that decision.
Teacher questions
The teacher could ask:
- What is the important information in the question?
- What sort of answer is expected?
- What part of the text tells you this?
- What should the answer look like?
- is it a number?
- does it have units?
- if so, what units should be used?
Example using this recognition strategy
The below example demonstrates how this strategy could be used in a Year 8 unit on money.
Problem
Aiden bought a pair of sneakers on the internet for $80. He then sold them for $100.
Find the profit as a percentage of the cost.
- A. 20
- B. $20
- C. 50%
- D. 25
- E. 25%
Recongising appropriate answers
The teacher asks students to highlight the key word/s in the question that indicates the type of answer expected (i.e. percentage)
The teacher asks students to look at the options for answers to check which could be possible.
Solution
Options C and E are the only ones with percentage signs, so the answer has to be one of these.
Note: A and D have no units and B is an amount, not a percentage (in this case, $20 is the actual profit)
If C was correct then the profit would be $40, which is not the case, so the answer is E.