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Basic Math/percentage change


i have received the exam results for all the pupils in a primary school in Africa (grade 1-7). Each grade's mark is calculated out of a different total. I have therefore figured out the percentages for each class and the average percentage in each class.
I now want to compare them to the previous years results. However the total marks for each grades exams are different again, so I found the percentage average.

to find the percentage difference is it still necessary to *100 as I am already working with percentages?

2013: 58%
2014: 67%

% Diff
67 - 58 = 9
9/67 = 0.13

is 0.13 the percentage change or do I still need to *100, therefore 13%. I am already working with percentages so am not sure.

% Diff
67 - 58 = 9

That's actually just the difference between 67 and 58 at this point, no longer percentages, so yes, you'd have to convert the final answer to a percentage.  

HOWEVER, it should be 9/58 or 15%, not 9/67 = 0.13

58 + .15(58) = 67  

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Lynn Houston


I can answer questions in basic algebra and any grade school math.


Love math, currently helping my nephew get through Intermediate Algebra.

I majored in Math Ed in college (but decided not to teach), so have over 40 credits of math.

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