What does the empirical formula of this mixture of iron oxides tell you about its consituents?

Which dilutions can you make using only 10ml pipettes?

Scientists often require solutions which are diluted to a particular concentration. In this problem, you can explore the mathematics of simple dilutions

Can you see how to build a harmonic triangle? Can you work out the next two rows?

The harmonic triangle is built from fractions with unit numerators using a rule very similar to Pascal's triangle.

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

Find the maximum value of 1/p + 1/q + 1/r where this sum is less than 1 and p, q, and r are positive integers.

Can you find the value of this function involving algebraic fractions for x=2000?

Which rational numbers cannot be written in the form x + 1/(y + 1/z) where x, y and z are integers?

A mother wants to share a sum of money by giving each of her children in turn a lump sum plus a fraction of the remainder. How can she do this in order to share the money out equally?

Which of these continued fractions is bigger and why?

The problem is how did Archimedes calculate the lengths of the sides of the polygons which needed him to be able to calculate square roots?

Explore the continued fraction: 2+3/(2+3/(2+3/2+...)) What do you notice when successive terms are taken? What happens to the terms if the fraction goes on indefinitely?