Currency Conversion

Currency conversion involves changing values between different currencies using exchange rates. This is a real-life application of ratio and unit conversions, and requires careful multiplication or division depending on the context.

Overview

Currency conversion means changing an amount of money from one currency into another.

To do this, you use an exchange rate.

\( \text{new amount} = \text{old amount} \times \text{exchange rate} \)

In GCSE questions, you may need to convert from pounds to euros, dollars to pounds, or compare prices in different currencies.

What you should understand after this topic

  • Understand what an exchange rate means
  • Know when to multiply and when to divide
  • Convert between different currencies
  • Round money correctly
  • Solve exam-style foreign money problems

Key Definitions

Currency

A type of money used in a country, such as pounds, euros or dollars.

Exchange Rate

The rate used to convert one currency into another.

Convert

Change from one unit or currency to another.

Foreign Currency

Money from another country.

Equivalent Value

The same amount of money expressed in a different currency.

Rounding Money

Usually to 2 decimal places because money is normally written to the nearest cent or penny.

Key Rules

Multiply if the rate is “for 1”

Example: £1 = €1.20, so pounds to euros means multiply by 1.20.

Divide to go backwards

If you want euros back to pounds, divide by 1.20.

Read the rate carefully

The direction of the exchange rate matters.

Round money sensibly

Usually to 2 decimal places unless told otherwise.

Quick Recognition

£1 = €1.20

Pounds to euros: multiply by 1.20

€ to £

Go back by dividing by 1.20

Same direction

Use the rate as given

Opposite direction

Use the inverse operation

How to Solve

What is currency conversion?

Currency conversion means changing money from one currency into another using an exchange rate.

Currency conversion is a real-life application of ratio introduction.

Main idea

Always read the exchange rate carefully before deciding whether to multiply or divide.

Currency conversion example showing pounds euros and dollars with exchange rates and calculations

Understanding exchange rates

£1 = €1.20
This means every 1 pound is worth 1.20 euros.
To change pounds into euros, multiply by 1.20, making sure the units are consistent as in units and conversions.
To change euros back into pounds, divide by 1.20.
Exam tip: Write the exchange rate above your working so you use it the correct way round.

How to decide whether to multiply or divide

Why this matters: Most currency mistakes happen when the exchange rate is used the wrong way round.

Going with the rate

If the rate says £1 = €1.20, then pounds to euros uses multiplication.

Going back the other way

Euros to pounds uses division.

Check the units

Write what you start with and what you want to end with.

Estimate

Use rough mental maths to check whether your answer makes sense.

Rounding money

Money is usually given to 2 decimal places.

\( £23.456 \approx £23.46 \)
Rounding money uses the same skills as place value and rounding.

Example Questions

Edexcel

Exam-style questions inspired by Edexcel GCSE Mathematics, focusing on converting between currencies using given exchange rates.

Edexcel

The exchange rate is £1 = €1.20. Convert £50 into euros.

Edexcel

The exchange rate is £1 = $1.35. Convert £80 into US dollars.

Edexcel

The exchange rate is £1 = €1.25. Convert €100 into pounds.

Edexcel

A camera costs $540. The exchange rate is £1 = $1.50. Find the cost in pounds.

Edexcel

The exchange rate is £1 = €1.18. How many euros can be bought with £250?

AQA

Exam-style questions based on the AQA GCSE Mathematics specification, emphasising multi-step conversions and real-life contexts.

AQA

The exchange rate is £1 = €1.20. A hotel costs €360. Find the cost in pounds.

AQA

The exchange rate is £1 = $1.25. A tablet costs $375. Calculate the price in pounds.

AQA

£1 = €1.15. A traveller converts £400 into euros and spends €275. How many euros remain?

AQA

The exchange rate is £1 = €1.20. After returning from holiday, Maria converts €90 back into pounds. How much does she receive?

AQA

Explain why the amount received when converting money back is often less than the original amount.

OCR

Exam-style questions aligned with OCR GCSE Mathematics, focusing on reasoning, proportional thinking, and financial decision-making.

OCR

The exchange rate is £1 = $1.40. How many dollars will you receive for £65?

OCR

The exchange rate is £1 = €1.25. How many pounds are equivalent to €250?

OCR

A flight costs €480. The exchange rate is £1 = €1.20. Find the cost in pounds.

OCR

Two exchange bureaux offer the following rates: Bureau A: £1 = €1.18, Bureau B: £1 = €1.22. Which offers the better value for converting £500 into euros?

OCR

Describe the steps required to convert from one currency to another using an exchange rate.

Exam Checklist

Step 1

Read the exchange rate very carefully.

Step 2

Decide which currency you start with and which one you want.

Step 3

Multiply or divide correctly.

Step 4

Round your answer appropriately and include the currency symbol.

Most common exam mistakes

Direction mistake

Using the exchange rate the wrong way round.

Operation mistake

Multiplying when you should divide, or dividing when you should multiply.

Money mistake

Not rounding to sensible money values.

Symbol mistake

Forgetting whether the answer is in pounds, euros or dollars.

Common Mistakes

These are common mistakes students make when solving currency conversion problems in GCSE Maths.

Multiplying instead of dividing

Incorrect

A student multiplies by the exchange rate when they should divide.

Correct

Decide whether to multiply or divide based on the direction of conversion. If converting to a stronger currency, you usually divide; if converting to a weaker currency, you multiply.

Misreading the exchange rate

Incorrect

A student uses the exchange rate in the wrong direction.

Correct

Always read the exchange rate carefully. For example, if \(1\text{ GBP} = 1.2\text{ EUR}\), then converting GBP to EUR means multiplying, but converting EUR to GBP means dividing.

Forgetting currency symbols

Incorrect

A student writes the answer without a currency symbol.

Correct

Always include the correct currency symbol (e.g. £, €, $) in your final answer, as marks may be awarded for this.

Rounding too early

Incorrect

A student rounds intermediate values before completing the calculation.

Correct

Do not round until the final answer. Early rounding can lead to inaccurate results.

Using incorrect decimal places

Incorrect

A student gives an answer with too many decimal places.

Correct

Money should usually be given to 2 decimal places (e.g. £12.45). Always check the required level of accuracy.

Try It Yourself

Practise converting between currencies using exchange rates.

Questions coming soon
Foundation

Foundation Practice

Convert between currencies using basic exchange rates.

Question 1

Exchange rate: £1 = €1.20. How many euros is £10?

Games

Practise this topic with interactive games.

Games coming soon.

Frequently Asked Questions