When is a knot invertible ?
All types of mathematical problems serve a useful purpose in
mathematics teaching, but different types of problem will achieve
different learning objectives. In generalmore open-ended problems
have. . . .
What's the chance of a pair of lists of numbers having sample
correlation exactly equal to zero?
How much energy has gone into warming the planet?
Work with numbers big and small to estimate and calculate various quantities in biological contexts.
Two polygons fit together so that the exterior angle at each end of
their shared side is 81 degrees. If both shapes now have to be
regular could the angle still be 81 degrees?
Explore the properties of combinations of trig functions in this open investigation.
This article (the first of two) contains ideas for investigations.
Space-time, the curvature of space and topology are introduced with
some fascinating problems to explore.
Two perpendicular lines lie across each other and the end points
are joined to form a quadrilateral. Eight ratios are defined, three
are given but five need to be found.
How much peel does an apple have?
Work with numbers big and small to estimate and calculate various quantities in physical contexts.
Investigate constructible images which contain rational areas.
Some of our more advanced investigations
We think this 3x3 version of the game is often harder than the 5x5 version. Do you agree? If so, why do you think that might be?
An introduction to a useful tool to check the validity of an equation.
Get some practice using big and small numbers in chemistry.
Work out the numerical values for these physical quantities.
Where we follow twizzles to places that no number has been before.
Take ten sticks in heaps any way you like. Make a new heap using one from each of the heaps. By repeating that process could the arrangement 7 - 1 - 1 - 1 ever turn up, except by starting with it?
Take any pair of numbers, say 9 and 14. Take the larger number,
fourteen, and count up in 14s. Then divide each of those values by
the 9, and look at the remainders.
Can you find some Pythagorean Triples where the two smaller numbers differ by 1?
On a "move" a stone is removed from two of the circles and placed
in the third circle. Here are five of the ways that 27 stones could
In a snooker game the brown ball was on the lip of the pocket but
it could not be hit directly as the black ball was in the way. How
could it be potted by playing the white ball off a cushion?
Where should runners start the 200m race so that they have all run the same distance by the finish?
Could nanotechnology be used to see if an artery is blocked? Or is this just science fiction?
Formulate and investigate a simple mathematical model for the design of a table mat.
Use trigonometry to determine whether solar eclipses on earth can be perfect.
In which Olympic event does a human travel fastest? Decide which events to include in your Alternative Record Book.
This tricky challenge asks you to find ways of going across rectangles, going through exactly ten squares.
A description of some experiments in which you can make discoveries about triangles.
Numbers arranged in a square but some exceptional spatial awareness probably needed.
A follow-up activity to Tiles in the Garden.
How many different sets of numbers with at least four members can you find in the numbers in this box?
An introduction to bond angle geometry.
The letters of the word ABACUS have been arranged in the shape of a
triangle. How many different ways can you find to read the word
ABACUS from this triangular pattern?
There are three tables in a room with blocks of chocolate on each. Where would be the best place for each child in the class to sit if they came in one at a time?
In this investigation, we look at Pascal's Triangle in a slightly different way - rotated and with the top line of ones taken off.
Is it really greener to go on the bus, or to buy local?
How will you decide which way of flipping over and/or turning the grid will give you the highest total?
It starts quite simple but great opportunities for number discoveries and patterns!
Explore one of these five pictures.
In this article for teachers, Bernard gives an example of taking an
initial activity and getting questions going that lead to other
What shapes should Elly cut out to make a witch's hat? How can she make a taller hat?
Investigate how this pattern of squares continues. You could
measure lengths, areas and angles.
A challenging activity focusing on finding all possible ways of stacking rods.
Many natural systems appear to be in equilibrium until suddenly a critical point is reached, setting up a mudslide or an avalanche or an earthquake. In this project, students will use a simple. . . .
This article for teachers suggests ideas for activities built around 10 and 2010.
There are nine teddies in Teddy Town - three red, three blue and three yellow. There are also nine houses, three of each colour. Can you put them on the map of Teddy Town according to the rules?
Have a go at this 3D extension to the Pebbles problem.
Place four pebbles on the sand in the form of a square. Keep adding as few pebbles as necessary to double the area. How many extra pebbles are added each time?