Investigate the effects of the half-lifes of the isotopes of cobalt on the mass of a mystery lump of the element.

See how the motion of the simple pendulum is not-so-simple after all.

Work in groups to try to create the best approximations to these physical quantities.

Get some practice using big and small numbers in chemistry.

Build up the concept of the Taylor series

Work out the numerical values for these physical quantities.

An advanced mathematical exploration supporting our series of articles on population dynamics for advanced students.

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

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

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

Looking at small values of functions. Motivating the existence of the Taylor expansion.

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

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?

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

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.

Practise your skills of proportional reasoning with this interactive haemocytometer.

Which is larger: (a) 1.000001^{1000000} or 2? (b) 100^{300} or 300! (i.e.factorial 300)