Marking an economics calculation with working
A percentage-change question shows how credit can follow the working when arithmetic goes wrong.
The question
Real GDP rises from $500 billion to $525 billion. Calculate the percentage increase. Show your working. (3 marks)
The marking guide
- Award 1 mark for a correct increase of $25 billion.
- Award 1 mark for dividing the increase by the original value and multiplying by 100: 25 / 500 × 100.
- Award 1 mark for the correct final answer of 5%. Award the method marks independently of the final arithmetic.
The sample response
Increase = 525 − 500 = 25 billion Percentage increase = (25 / 500) × 100 = 0.5%
Axtant’s mark and feedback
You correctly found the increase of $25 billion and used the correct method of dividing by the original value and multiplying by 100. Your final calculation is incorrect: the percentage increase is 5%, not 0.5%.
Why the guide matters here
The increase and method are correct. The final decimal is wrong, so the answer loses the accuracy mark while keeping the two method marks.
A useful teaching follow-up
Keep method and accuracy separate when the guide requires it. Here, recalculating the final line identifies the error without erasing correct working.
Try it with your material
This practice question, guide and sample response were written for Axtant. The mark and feedback shown are Axtant’s own for that response.