Depreciation (Cambridge (CIE) IGCSE Maths)
Revision Note
Depreciation
What does depreciation mean?
Depreciation is where an item loses value over time
E.g. cars, mobile phones, etc
Depreciation is usually calculated as a percentage decrease at the end of each year
This works the same as compound interest, but with a percentage decrease
How do I calculate depreciation?
A similar method to compound interest can be used
Change the multiplier to one which represents a percentage decrease
e.g. a decrease of 15% would be a multiplier of 0.85
If a car worth $ 16 000 depreciates by 15% each year for 6 years
Its value will be 16 000 × 0.856, which is $ 6034.39
If you are asked to find the amount the value has depreciated by:
Find the difference between the starting value and the new value
Depreciation formula
An alternate method is to use the following formula to calculate the final balance
Final balance = where
P is the original amount,
r is the % increase
and n is the number of years
Note that all of is the multiplier
e.g. 0.75 for a 25% depreciation
This formula is not given in the exam
Worked Example
Mercy buys a car for £20 000. Each year its value depreciates by 15%.
Find the value of the car after 3 full years.
Identify the multiplier
100% - 15% = 85%
m = 1 - 0.15 = 0.85
Raise to the power of number of years
0.853
Multiply by the starting value
£20 000 × 0.853
£12 282.50
Alternative method
Use the formula for the final amount
Substitute P = 20 000, r = 15 and n = 3 into the formula
£12 282.50
You've read 0 of your 5 free revision notes this week
Sign up now. It’s free!
Did this page help you?