# 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.

## 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 19 November 'Starter of the Day' page by Lesley Sewell, Ysgol Aberconwy, Wales:

"A Maths colleague introduced me to your web site and I love to use it. The questions are so varied I can use them with all of my classes, I even let year 13 have a go at some of them. I like being able to access the whole month so I can use favourites with classes I see at different times of the week. Thanks."

Comment recorded on the 19 October 'Starter of the Day' page by E Pollard, Huddersfield:

"I used this with my bottom set in year 9. To engage them I used their name and favorite football team (or pop group) instead of the school name. For homework, I asked each student to find a definition for the key words they had been given (once they had fun trying to guess the answer) and they presented their findings to the rest of the class the following day. They felt really special because the key words came from their own personal information."

#### Beat The Clock

It is a race against the clock to answer 30 mental arithmetic questions. There are nine levels to choose from to suit pupils of different abilities.

## 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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