Hi. There are loads of problems about percentage change!  A change is either an increase or a decrease and the wording varies such as ...

percentage increase?  percentage decrease? percentage discount? percentage payrise?  percentage improvement in marks? percentage profit?  percentage loss?  ...

BUT
- they all mean a PERCENTAGE CHANGE,
- and they are all worked out in the SAME WAY!
- So learn this method once and gets all percentage change questions correct in the future!

Method for Calculating Any Percentage Change:

%age change =  actual change        x   100 
                          original amount

Example of a Percentage Increase:
Sarah gets £10 a week pocket money.  Her parents decide to give her £12 a week.  What is the percentage increase in Sarah's pocket money?

Answer:
Actual  change (an increase)  = £2
Percentage increase               =  2   x  100  =  2  ÷ 10 X 100  =  0.2 x 100  =  20% 
                                                10
Sarah gets a 20% INCREASE in her pocket money.

Example of a Percentage Decrease:
Liana gets £10 a week pocket money.  Her parents decide to reduce it to £8 a week.  What is the percentage decrease in Liana's pocket money?

Answer:
Actual change (a decrease)    = £2
Percentage decrease              =  2   x  100  =  2  ÷ 10 X 100  =  0.2 x 100  =  20%
                                                10
Liana gets a 20% DECREASE in her pocket money.