GCSE Maths Practice: currency-conversion

Converting Larger Amounts of Money

Currency conversion is a key GCSE Maths topic that applies proportional reasoning to real-life money situations. While smaller amounts help build confidence, exam questions often include larger values to test whether students can apply the same method consistently and accurately.

What an Exchange Rate Tells You

An exchange rate compares the value of two currencies. For example, if £1 = €1.20, this means that every pound is worth one euro and twenty cents. When converting from pounds to euros using this rate, the amount in euros will always be larger than the amount in pounds.

Recognising this relationship helps you decide whether your answer should be bigger or smaller before you calculate.

Choosing the Correct Calculation

At GCSE Foundation level, currency conversion usually follows a simple rule:

• Pounds to euros → multiply by the exchange rate
• Euros to pounds → divide by the exchange rate

Before calculating, take a moment to predict the size of the answer. This step is especially useful in multiple-choice questions.

Worked Example (Different Numbers)

Suppose the exchange rate is £1 = €1.30.

Which option correctly shows the value of £150 in euros?

Step 1: Estimate first. £150 × 1.3 is just under £150 × 1.5, so the answer should be just under €200.

Step 2: Multiply: 150 × 1.30 = 195

Step 3: Write the amount as money → €195.00

Another Example

If £1 = €0.85 and someone exchanges £300:

300 × 0.85 = 255 → €255.00

Common Mistakes with Larger Numbers

• Misplacing the decimal point: Always double-check decimal multiplication.
• Skipping estimation: This makes it harder to spot unreasonable answers.
• Choosing an option without calculating: Guessing often leads to errors.
• Forgetting the currency symbol: Correct notation matters in GCSE exams.

Real-Life Uses of Large Currency Conversions

Converting larger sums of money is common in real life, for example:

• Budgeting for holidays or travel expenses
• Paying for accommodation abroad
• Comparing large purchases on international websites
• Planning costs for school trips or events

Frequently Asked Questions

Are large numbers harder in currency conversion?
The method is exactly the same. Only the size of the calculation changes.

Should I always estimate first?
Yes. Estimation helps eliminate incorrect options quickly.

Do Foundation questions use complex exchange rates?
No. Exchange rates are usually simple decimals such as 1.2 or 0.9.

Study Tip

For multiple-choice questions, estimate first to rule out impossible answers, then confirm the correct option with a clear calculation.