# Compound Interest Calculator

## A customised online calculator for quickly finding the solutions to compound interest problems.

##### Compound Interest CalculatorOnline ExerciseExam-StyleMore Calculator Activities
Present Value (PV): \$ £ € ¥ ₹ 元 THB % %

Compound interest can be calculated by using the following formula to calculate the final amount or future value (FV)

$$FV = PV(1 + \frac{r}{100})^n$$

$$PV$$ is the present value.

$$n$$ is the number of years.

$$r$$ is the rate of interest.

or by using the iterative function

$$x_{n+1} = x_n + \frac{x_n \times r}{100}$$

where $$x_0$$ is the present value [See Calculator Workout Skill 16]

$$FV = PV(1 + \frac{r}{100k})^{kn}$$

$$PV$$ is the present value.

$$n$$ is the number of years.

$$r$$ is the rate of interest.

$$k$$ is the number of compounding periods per year.

To calculate depreciation use a negative interest rate (r).

## Transum.org

This web site contains over a thousand free mathematical activities for teachers and pupils. Click here to go to the main page which links to all of the resources available.

## More Activities:

Mathematicians are not the people who find Maths easy; they are the people who enjoy how mystifying, puzzling and hard it is. Are you a mathematician?

Comment recorded on the 24 May 'Starter of the Day' page by Ruth Seward, Hagley Park Sports College:

"Find the starters wonderful; students enjoy them and often want to use the idea generated by the starter in other parts of the lesson. Keep up the good work"

Comment recorded on the 28 May 'Starter of the Day' page by L Smith, Colwyn Bay:

"An absolutely brilliant resource. Only recently been discovered but is used daily with all my classes. It is particularly useful when things can be saved for further use. Thank you!"

#### Without Lifting

Can you draw these diagrams without lifting your pencil from the paper? This is an interactive version of the traditional puzzle. Some diagrams are possible while others are not. What is the rule?

## Numeracy

"Numeracy is a proficiency which is developed mainly in Mathematics but also in other subjects. It is more than an ability to do basic arithmetic. It involves developing confidence and competence with numbers and measures. It requires understanding of the number system, a repertoire of mathematical techniques, and an inclination and ability to solve quantitative or spatial problems in a range of contexts. Numeracy also demands understanding of the ways in which data are gathered by counting and measuring, and presented in graphs, diagrams, charts and tables."

Secondary National Strategy, Mathematics at key stage 3

## Go Maths

Learning and understanding Mathematics, at every level, requires learner engagement. Mathematics is not a spectator sport. Sometimes traditional teaching fails to actively involve students. One way to address the problem is through the use of interactive activities and this web site provides many of those. The Go Maths main page links to more activities designed for students in upper Secondary/High school.

## Teachers

If you found this activity useful don't forget to record it in your scheme of work or learning management system. The short URL, ready to be copied and pasted, is as follows:

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