Bluey-green, white and transparent squares with a few odd bits of shapes around the perimeter. But, how many squares are there of each type in the complete circle? Study the picture and make. . . .

Sissa cleverly asked the King for a reward that sounded quite modest but turned out to be rather large...

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

Unmultiply is a game of quick estimation. You need to find two numbers that multiply together to something close to the given target - fast! 10 levels with a high scores table.

There are nasty versions of this dice game but we'll start with the nice ones...

Dicey Operations for an adult and child. Can you get close to 1000 than your partner?

Some Games That May Be Nice or Nasty for an adult and child. Use your knowledge of place value to beat your oponent.

Here is a chance to play a version of the classic Countdown Game.

Who said that adding, subtracting, multiplying and dividing couldn't be fun?

Get some practice using big and small numbers in chemistry.

How might you use mathematics to improve your chances of guessing the number of sweets in a jar?

Work out the numerical values for these physical quantities.

Examine these estimates. Do they sound about right?

10 graphs of experimental data are given. Can you use a spreadsheet to find algebraic graphs which match them closely, and thus discover the formulae most likely to govern the underlying processes?

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

Practise your skills of proportional reasoning with this interactive haemocytometer.

How many generations would link an evolutionist to a very distant ancestor?

In this twist on the well-known Countdown numbers game, use your knowledge of Powers and Roots to make a target.

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

Can you work out how many of each kind of pencil this student bought?