Teaching mathematics
Teaching mathematics

Start this free course now. Just create an account and sign in. Enrol and complete the course for a free statement of participation or digital badge if available.

Free course

Teaching mathematics

Exchange rates

A common use for proportionality is currency exchange rates. When you change your money at the Post Office or travel agent ‘commission free’, they will use a different exchange rate when they sell you foreign currency to when they buy it, thus making a profit.

Activity 10 Example problem: Japanese yen

Timing: Allow 5 minutes

Zoë is going on holiday from England to Japan.

Before leaving, she changes 1500 pounds sterling (GBP) into Japanese yen (JPY).

The exchange rate is 1 GBP = 177.415 JPY.

Calculate the amount of foreign currency Zoë takes on holiday.

Discussion

This question is quite straightforward since you are given the unit rate for £1 in yen. All that is required here is to multiply the number of pounds by the rate, giving 266 122.50 yen.

If the rate was given in another form, for instance: 20 GBP = 3548.30 JPY, another step would be needed to calculate the unit rate.

TM_1

Take your learning further

Making the decision to study can be a big step, which is why you'll want a trusted University. The Open University has 50 years’ experience delivering flexible learning and 170,000 students are studying with us right now. Take a look at all Open University courses.

If you are new to university level study, find out more about the types of qualifications we offer, including our entry level Access courses and Certificates.

Not ready for University study then browse over 900 free courses on OpenLearn and sign up to our newsletter to hear about new free courses as they are released.

Every year, thousands of students decide to study with The Open University. With over 120 qualifications, we’ve got the right course for you.

Request an Open University prospectus