Working with appreciation and depreciationDepreciation

Appreciation, depreciation and compound interest can all be calculated using the multiplier method.

Part ofMathsNumerical skills

Depreciation

Depreciation refers to when the value of something goes down over time.

The value of a car is usually decreases in value with time. Therefore its value is said to .

Example

Jack and Trisha bought a new car for £8500 in 2009. In the first year, its value depreciated by 20%, in the second year by 15% and in the third by 10%.

Calculate the value of the car at the end of each year.

Answer

Value at the end of Year 1:

Percentage has gone down by 20%, therefore 100% - 20% = 80%

\(80\% \,of\,8500\)

\(= 0.8 \times 8500\)

\(= \pounds6800\) (Another way of doing this calculation is to find 20% and then subtract)

Value at the end of Year 2:

Percentage has gone down by 15%, therefore 100% - 15% = 85%

\(85\% \,of\,6800\)

\(= 0.85 \times 6800\)

\(= \pounds5780\)

Value at the end of Year 3:

Percentage has gone down by 10%, therefore 100% - 10% = 90%

\(90\% \,of\,5780\)

\(= 0.9 \times 5780\)

\(= \pounds5202\)

Now try the example questions below.

Question

Jean bought an antique ring for £200. Its value appreciates by 10% each year.

Calculate the value of the ring after 10 years.

Question

Ahmed bought a car for £6000. It depreciated at 17% per year for the next 3 years. How much was it worth after 3 years.