Exam-style question
Try this first
A learner writes: "√2 is not an irrational number because it is written using a square-root symbol rather than as a number." Explain why this reasoning is incorrect.
Model answer
What a good answer should say
- The notation used does not determine whether a number is irrational.
- √2 is identified as an irrational number because it cannot be written as a fraction.
- Therefore, using a square-root symbol does not make the learner's conclusion correct.
Explanation
Why this works
The key test in the specification is whether the number can be written as a fraction, not which symbol is used to write it. A strong answer identifies the incorrect focus on notation and replaces it with the correct definition.
Common mistake
No common mistake is linked to this question yet.