10th October 2003 at 01:00
Modern-day banking involves electronic transfer of vast amounts of money between accounts all over the world. There is no physical movement, but billions of pounds worth of transactions take place each day. These must be secure, or fraud on a massive scale would be possible.

* Security is ensured using codes and encryption, made possible by an application of number theory and involving the use of very large prime numbers. Understanding the basis of such techniques is within the capabilities of upper secondary students.

* Codes and encryption are a rich source of maths from junior school upwards and have a colourful history, relating to the transfer of secret military and political information, as well as in finance and business. Two good books covering this area, both containing many ideas that could be adapted for the classroom, are: Simon Singh's The Code Book (a history of codes and code-breaking) and Sarah Flannery's In Code, which tells the story of a 16-year-old Irish girl who won the 1999 young European scientist of the year award for inventing a system for encrypting data on the internet. This contains lots of entertaining maths suitable for secondary pupils. Simon Singh also has a website that gives information on codes and encryption:, and he has produced an interactive CD suitable for classroom use.

Log-in as an existing print or digital subscriber

Forgotten your subscriber ID?


To access this content and the full TES archive, subscribe now.

View subscriber offers


Get TES online and delivered to your door – for less than the price of a coffee

Save 33% off the cover price with this great subscription offer. Every copy delivered to your door by first-class post, plus full access to TES online and the TES app for just £1.90 per week.
Subscribers also enjoy a range of fantastic offers and benefits worth over £270:

  • Discounts off TES Institute courses
  • Access over 200,000 articles in the TES online archive
  • Free Tastecard membership worth £79.99
  • Discounts with Zipcar,, Virgin Wines and other partners
Order your low-cost subscription today