Money

2026 Syllabus Objectives

By the end of this topic, you should be able to:

  1. Calculate with money
  2. Convert from one currency to another

What is Money in Mathematics?

Money is a way to measure value and make purchases. In mathematics, we work with money by doing calculations (adding, subtracting, multiplying, dividing) and converting between different types of money called currencies.

Different countries use different currencies. Each currency has its own name and symbol.

Common Currencies

The most commonly used currencies you'll encounter are:

  • US Dollars – written as $ or USD
  • Great British Pounds – written as £ or GBP
  • Euros – written as € or EUR
  • Pakistani Rupees – written as PKR or Rs

You may also see other currencies in exam questions, sometimes with symbols and sometimes without.

Calculating with Money

When working with money, you'll need to perform basic calculations. Look for key words in questions to know what operation to use:

Addition – when you see words like:

  • Total
  • Sum
  • Combined cost
  • Altogether

Subtraction – when you see words like:

  • Difference
  • Change (money left over)
  • Increase or decrease in cost
  • How much more/less

Multiplication – when you see:

  • Cost of multiple items
  • Converting currencies

Division – when you see:

  • Sharing costs equally
  • Converting currencies
  • Finding unit price

Rounding Money Values

Most currencies are rounded to two decimal places (two numbers after the decimal point). This applies to dollars, pounds, and euros.

Important rules:

  • Always write both decimal places, even if the second digit is zero
  • For example, 1.4 dollars on a calculator should be written as **1.40(not1.40** (not1.4)

Example:

  • Correct: £5.20
  • Incorrect: £5.2

For large amounts (like the cost of a car), you might round to the nearest dollar, 10 dollars, or 100 dollars instead. Use the context of the question to decide what's appropriate.

Some currencies have very large numbers due to exchange rates (like rupees). These are usually rounded to the nearest whole number.

Example: If 10=816.38rupees,youcouldroundtheexchangeratesothat10 = 816.38 rupees, you could round the exchange rate so that100 = 8160 rupees.

Working with More Than Two Decimal Places

Sometimes prices are given with more than two decimal places.

Example: Petrol in the UK might cost £1.579 per litre.

Rule: Use all the decimal places given in your working and calculations. Only round your final answer to two decimal places (or whatever is appropriate for the question).

Converting Currencies

Currency conversion means changing money from one currency to another. This uses an exchange rate, which tells you how much of one currency equals another.

There are several methods to convert currencies.

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