This activity challenges you to decide on the 'best' number to use in each statement. You may need to do some estimating, some calculating and some research.

Can you put these times on the clocks in order? You might like to arrange them in a circle.

Can you place these quantities in order from smallest to largest?

Can you order pictures of the development of a frog from frogspawn and of a bean seed growing into a plant?

Can you rank these quantities in order? You may need to find out extra information or perform some experiments to justify your rankings.

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

Can you rank these sets of quantities in order, from smallest to largest? Can you provide convincing evidence for your rankings?

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

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?

Thomas from Colet Court and pupils from Kingsbury Green Primary worked particularly thoughtfully on this problem.