Is it cheaper to cook a meal from scratch or to buy a ready meal? What difference does the number of people you're cooking for make?

If I don't have the size of cake tin specified in my recipe, will the size I do have be OK?

How would you go about estimating populations of dolphins?

The triathlon is a physically gruelling challenge. Can you work out which athlete burnt the most calories?

Many physical constants are only known to a certain accuracy. Explore the numerical error bounds in the mass of water and its constituents.

Invent a scoring system for a 'guess the weight' competition.

Can you sketch graphs to show how the height of water changes in different containers as they are filled?

Make your own pinhole camera for safe observation of the sun, and find out how it works.

Examine these estimates. Do they sound about right?

To investigate the relationship between the distance the ruler drops and the time taken, we need to do some mathematical modelling...

Which dilutions can you make using only 10ml pipettes?

What shape would fit your pens and pencils best? How can you make it?

Two trains set off at the same time from each end of a single straight railway line. A very fast bee starts off in front of the first train and flies continuously back and forth between the. . . .

These Olympic quantities have been jumbled up! Can you put them back together again?

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

Work with numbers big and small to estimate and calulate various quantities in biological contexts.

Work with numbers big and small to estimate and calculate various quantities in biological contexts.

Where should runners start the 200m race so that they have all run the same distance by the finish?

Could nanotechnology be used to see if an artery is blocked? Or is this just science fiction?

Formulate and investigate a simple mathematical model for the design of a table mat.

In which Olympic event does a human travel fastest? Decide which events to include in your Alternative Record Book.

Get some practice using big and small numbers in chemistry.

Make an accurate diagram of the solar system and explore the concept of a grand conjunction.

Use trigonometry to determine whether solar eclipses on earth can be perfect.

Work with numbers big and small to estimate and calculate various quantities in physical contexts.

When you change the units, do the numbers get bigger or smaller?

Which units would you choose best to fit these situations?

Use your skill and knowledge to place various scientific lengths in order of size. Can you judge the length of objects with sizes ranging from 1 Angstrom to 1 million km with no wrong attempts?

Work out the numerical values for these physical quantities.

Explore the relationship between resistance and temperature

Water freezes at 0°Celsius (32°Fahrenheit) and boils at 100°C (212°Fahrenheit). Is there a temperature at which Celsius and Fahrenheit readings are the same?

Analyse these beautiful biological images and attempt to rank them in size order.

Estimate these curious quantities sufficiently accurately that you can rank them in order of size

This problem explores the biology behind Rudolph's glowing red nose.

Practice your skills of measurement and estimation using this interactive measurement tool based around fascinating images from biology.

What shapes should Elly cut out to make a witch's hat? How can she make a taller hat?

Andy wants to cycle from Land's End to John o'Groats. Will he be able to eat enough to keep him going?

Can you suggest a curve to fit some experimental data? Can you work out where the data might have come from?

Have you ever wondered what it would be like to race against Usain Bolt?

Which countries have the most naturally athletic populations?

Can you work out which processes are represented by the graphs?