
Investigate Farey sequences of ratios of Fibonacci numbers.

Use Farey sequences to obtain rational approximations to irrational numbers.

How do you choose your planting levels to minimise the total loss at harvest time?

Can you find the maximum value of the curve defined by this expression?

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

Small circles nestle under touching parent circles when they sit on the axis at neighbouring points in a Farey sequence.
In this article Jenny talks about Assessing Pupils' Progress and the use of NRICH problems.
This article sets some puzzles and describes how Euclid's algorithm and continued fractions are related.
The first of three articles on the History of Trigonometry. This takes us from the Egyptians to early work on trigonometry in China.