This problem explores the range of events in a sports day and which ones are the most popular and attract the most entries.

You may like to read the article on Morse code before attempting this question. Morse's letter analysis was done over 150 years ago, so might there be a better allocation of symbols today?

In this problem you will do your own poll to find out whether your friends think two squares on a board are the same colour or not.

Have a look at this table of how children travel to school. How does it compare with children in your class?

Letters have different values in Scrabble - how are they decided upon? And would the values be the same for other languages?

This problem offers you two ways to test reactions - use them to investigate your ideas about speeds of reaction.

Build a mini eco-system, and collect and interpret data on how well the plants grow under different conditions.

When Charlie retires, he's looking forward to the quiet life, whereas Alison wants a busy and exciting retirement. Can you advise them on where they should go?

Six samples were taken from two distributions but they got muddled up. Can you work out which list is which?

Substitution and Transposition all in one! How fiendish can these codes get?

Can you deduce which Olympic athletics events are represented by the graphs?

How have "Warmsnug" arrived at the prices shown on their windows? Which window has been given an incorrect price?

How do decisions about scoring affect who wins a combined event such as the decathlon?

Here is the start of a six-part challenge. Can you get to the end and crack the final message?

Find the frequency distribution for ordinary English, and use it to help you crack the code.

Can you put these mixed-up times in order? You could arrange them in a circle.