List

Visualising - Upper Secondary

Introducing NRICH TWILGO
interactivity

Introducing NRICH TWILGO

Age
5 to 18
Challenge level
filled star empty star empty star
We're excited about this new program for drawing beautiful mathematical designs. Can you work out how we made our first few pictures and, even better, share your most elegant solutions with us?
Pumpkin Patch
game

Pumpkin patch

Age
5 to 18
A game for two players based on a game from the Somali people of Africa. The first player to pick all the other's 'pumpkins' is the winner.
Seega
game

Seega

Age
5 to 18
An ancient game for two from Egypt. You'll need twelve distinctive 'stones' each to play. You could chalk out the board on the ground - do ask permission first.
Alquerque
game

Alquerque

Age
5 to 18
This game for two, was played in ancient Egypt as far back as 1400 BC. The game was taken by the Moors to Spain, where it is mentioned in 13th century manuscripts, and the Spanish name Alquerque derives from the Arabic El- quirkat. Watch out for being 'huffed'.
Prime Magic
problem

Prime magic

Age
7 to 16
Challenge level
filled star filled star empty star
Place the numbers 1, 2, 3,..., 9 one on each square of a 3 by 3 grid so that all the rows and columns add up to a prime number. How many different solutions can you find?
Like a Circle in a Spiral
problem

Like a circle in a spiral

Age
7 to 16
Challenge level
filled star empty star empty star
A cheap and simple toy with lots of mathematics. Can you interpret the images that are produced? Can you predict the pattern that will be produced using different wheels?
Fruity Totals
problem

Fruity totals

Age
7 to 16
Challenge level
filled star empty star empty star

In this interactivity each fruit has a hidden value. Can you deduce what each one is worth?

Cubic Conundrum
problem

Cubic conundrum

Age
7 to 16
Challenge level
filled star filled star filled star
Which of the following cubes can be made from these nets?
Air Nets
problem

Air nets

Age
7 to 18
Challenge level
filled star empty star empty star
Can you visualise whether these nets fold up into 3D shapes? Watch the videos each time to see if you were correct.
Clocking off
problem

Clocking off

Age
7 to 16
Challenge level
filled star empty star empty star
I found these clocks in the Arts Centre at the University of Warwick intriguing - do they really need four clocks and what times would be ambiguous with only two or three of them?
Wipeout
problem

Wipeout

Age
11 to 16
Challenge level
filled star filled star empty star

Can you do a little mathematical detective work to figure out which number has been wiped out?

Ding Dong Bell
article

Ding dong bell

The reader is invited to investigate changes (or permutations) in the ringing of church bells, illustrated by braid diagrams showing the order in which the bells are rung.
Take Three From Five
problem

Take three from five

Age
11 to 16
Challenge level
filled star filled star empty star

Caroline and James pick sets of five numbers. Charlie tries to find three that add together to make a multiple of three. Can they stop him?

Who's who?
problem

Who's who?

Age
11 to 16
Challenge level
filled star filled star empty star

Can you solve the clues to find out who's who on the friendship graph?

Charting success
problem

Charting success

Age
11 to 16
Challenge level
filled star empty star empty star
Can you make sense of the charts and diagrams that are created and used by sports competitors, trainers and statisticians?
Charting more success
problem

Charting more success

Age
11 to 16
Challenge level
filled star empty star empty star
Can you make sense of the charts and diagrams that are created and used by sports competitors, trainers and statisticians?
What is the question?
problem

What is the question?

Age
11 to 16
Challenge level
filled star empty star empty star
These pictures and answers leave the viewer with the problem "What is the Question". Can you give the question and how the answer follows?
11x11 square
problem

11x11 square

Age
11 to 16
Challenge level
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Here's a neat trick you can do with an 11 by 11 square...
Yih or Luk tsut k'i or Three Men's Morris
game

Yih or Luk tsut k'i or Three Men's Morris

Age
11 to 18
Challenge level
filled star empty star empty star

Some puzzles requiring no knowledge of knot theory, just a careful inspection of the patterns. A glimpse of the classification of knots and a little about prime knots, crossing numbers and knot arithmetic.

Spots and Measles
problem

Spots and measles

Age
11 to 16
Challenge level
filled star filled star empty star

99% of people who have measles have spots. Ben has spots. Do you think he has measles?

Shaping the universe I - planet Earth
article

Shaping the universe I - planet Earth

This article explores ths history of theories about the shape of our planet. It is the first in a series of articles looking at the significance of geometric shapes in the history of astronomy.

Sprouts
game

Sprouts

Age
11 to 16
Challenge level
filled star filled star empty star
A game for 2 people. Take turns joining two dots, until your opponent is unable to move.
Multiple Surprises
problem

Multiple surprises

Age
11 to 16
Challenge level
filled star empty star empty star

Sequences of multiples keep cropping up...

Marbles in a box
problem

Marbles in a box

Age
11 to 16
Challenge level
filled star filled star empty star

How many winning lines can you make in a three-dimensional version of noughts and crosses?

Placeholder: several colourful numbers
problem

Triangles in the middle

Age
11 to 18
Challenge level
filled star empty star empty star
This task depends on groups working collaboratively, discussing and reasoning to agree a final product.
Pythagoras Proofs
problem

Pythagoras proofs

Age
11 to 16
Challenge level
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Can you make sense of these three proofs of Pythagoras' Theorem?

Hamiltonian Cube
problem

Hamiltonian cube

Age
11 to 16
Challenge level
filled star filled star empty star
Weekly Problem 36 - 2007
Find the length along the shortest path passing through certain points on the cube.
The Triangle Game
game

The triangle game

Age
11 to 16
Challenge level
filled star empty star empty star
Can you discover whether this is a fair game?
Instant Insanity
problem

Instant insanity

Age
11 to 18
Challenge level
filled star filled star filled star

Given the nets of 4 cubes with the faces coloured in 4 colours, build a tower so that on each vertical wall no colour is repeated, that is all 4 colours appear.

Funny Factorisation
problem

Funny factorisation

Age
11 to 16
Challenge level
filled star filled star empty star

Using the digits 1 to 9, the number 4396 can be written as the product of two numbers. Can you find the factors?

Charlie's delightful machine
problem

Charlie's delightful machine

Age
11 to 16
Challenge level
filled star empty star empty star

Here is a machine with four coloured lights. Can you develop a strategy to work out the rules controlling each light?

Triangle in a Trapezium
problem

Triangle in a trapezium

Age
11 to 16
Challenge level
filled star filled star empty star

Can you find and prove the relationship between the area of a trapezium and the area of a triangle constructed within it?

Nine Colours
problem

Nine colours

Age
11 to 16
Challenge level
filled star filled star filled star

Can you use small coloured cubes to make a 3 by 3 by 3 cube so that each face of the bigger cube contains one of each colour?

What's it worth?
problem

What's it worth?

Age
11 to 16
Challenge level
filled star empty star empty star

There are lots of different methods to find out what the shapes are worth - how many can you find?

The Bridges of Konigsberg
problem

The bridges of Konigsberg

Age
11 to 18
Challenge level
filled star empty star empty star

Investigate how networks can be used to solve a problem for the 18th Century inhabitants of Konigsberg.

Searching for mean(ing)
problem

Searching for mean(ing)

Age
11 to 16
Challenge level
filled star filled star empty star

If you have a large supply of 3kg and 8kg weights, how many of each would you need for the average (mean) of the weights to be 6kg?

Sliding Puzzle
game

Sliding puzzle

Age
11 to 16
Challenge level
filled star empty star empty star
The aim of the game is to slide the green square from the top right hand corner to the bottom left hand corner in the least number of moves.
Cuboid challenge
problem

Cuboid challenge

Age
11 to 16
Challenge level
filled star filled star empty star

What's the largest volume of box you can make from a square of paper?

Vector Racer
game
Favourite

Vector racer

Age
11 to 16
Challenge level
filled star empty star empty star

The classic vector racing game.

LOGO Challenge - Triangles-Squares-Stars
problem

LOGO challenge - triangles-squares-stars

Age
11 to 16
Challenge level
filled star filled star empty star

Can you recreate these designs? What are the basic units? What movement is required between each unit? Some elegant use of procedures will help - variables not essential.

A Problem of time
problem

A problem of time

Age
14 to 16
Challenge level
filled star filled star filled star
Consider a watch face which has identical hands and identical marks for the hours. It is opposite to a mirror. When is the time as read direct and in the mirror exactly the same between 6 and 7?
Immersion
problem

Immersion

Age
14 to 16
Challenge level
filled star filled star empty star

Various solids are lowered into a beaker of water. How does the water level rise in each case?

Triangles within Squares
problem

Triangles within squares

Age
14 to 16
Challenge level
filled star filled star empty star
Can you find a rule which relates triangular numbers to square numbers?
Perception versus reality
problem

Perception versus reality

Age
14 to 18
Challenge level
filled star empty star empty star

Infographics are a powerful way of communicating statistical information. Can you come up with your own?

Travelator
problem

Travelator

Age
14 to 16
Challenge level
filled star filled star empty star
When Andrew arrives at the end of the walkway, how far is he ahead of Bill?
Terminology
problem

Terminology

Age
14 to 16
Challenge level
filled star filled star empty star

Given an equilateral triangle inside an isosceles triangle, can you find a relationship between the angles?

Facial Sums
problem

Facial sums

Age
14 to 16
Challenge level
filled star filled star empty star
Can you make the numbers around each face of this solid add up to the same total?
Making Tracks
problem

Making tracks

Age
14 to 16
Challenge level
filled star filled star empty star
A bicycle passes along a path and leaves some tracks. Is it possible to say which track was made by the front wheel and which by the back wheel?
All Tied Up
problem

All tied up

Age
14 to 16
Challenge level
filled star filled star empty star
A ribbon runs around a box so that it makes a complete loop with two parallel pieces of ribbon on the top. How long will the ribbon be?
Filling the gaps
problem

Filling the gaps

Age
14 to 16
Challenge level
filled star filled star empty star

Which numbers can we write as a sum of square numbers?

Hypotenuse Lattice points
problem

Hypotenuse lattice points

Age
14 to 16
Challenge level
filled star filled star filled star
The triangle OMN has vertices on the axes with whole number co-ordinates. How many points with whole number coordinates are there on the hypotenuse MN?
At right angles
problem

At right angles

Age
14 to 16
Challenge level
filled star filled star empty star

Can you decide whether two lines are perpendicular or not? Can you do this without drawing them?

Triangles within Pentagons
problem

Triangles within pentagons

Age
14 to 16
Challenge level
filled star filled star filled star
Show that all pentagonal numbers are one third of a triangular number.
Iff
problem

Iff

Age
14 to 18
Challenge level
filled star filled star empty star

Take a triangular number, multiply it by 8 and add 1. What is special about your answer? Can you prove it?

Tennis Training
problem

Tennis training

Age
14 to 16
Challenge level
filled star filled star empty star
After tennis training, Andy, Roger and Maria collect up the balls. Can you work out how many Andy collects?
Centre Square
problem

Centre square

Age
14 to 16
Challenge level
filled star filled star filled star
What does Pythagoras' Theorem tell you about the radius of these circles?
Bendy Quad
problem

Bendy quad

Age
14 to 16
Challenge level
filled star filled star filled star

Four rods are hinged at their ends to form a convex quadrilateral. Investigate the different shapes that the quadrilateral can take. Be patient this problem may be slow to load.

One Out One Under
problem

One out one under

Age
14 to 16
Challenge level
filled star filled star filled star
Imagine a stack of numbered cards with one on top. Discard the top, put the next card to the bottom and repeat continuously. Can you predict the last card?
Which list is which?
problem

Which list is which?

Age
14 to 16
Challenge level
filled star filled star empty star

Six samples were taken from two distributions but they got muddled up. Can you work out which list is which?

Star Gazing
problem

Star gazing

Age
14 to 16
Challenge level
filled star empty star empty star
Find the ratio of the outer shaded area to the inner area for a six pointed star and an eight pointed star.
Curvy areas
problem

Curvy areas

Age
14 to 16
Challenge level
filled star empty star empty star

Have a go at creating these images based on circles. What do you notice about the areas of the different sections?

Mixing More Paints
problem

Mixing more paints

Age
14 to 16
Challenge level
filled star filled star filled star

Can you find an efficent way to mix paints in any ratio?

Box plot match
problem

Box plot match

Age
14 to 16
Challenge level
filled star empty star empty star

Match the cumulative frequency curves with their corresponding box plots.

Tetra Square
problem

Tetra square

Age
14 to 18
Challenge level
filled star filled star empty star
ABCD is a regular tetrahedron and the points P, Q, R and S are the midpoints of the edges AB, BD, CD and CA. Prove that PQRS is a square.
Mystic Rose
problem

Mystic rose

Age
14 to 16
Challenge level
filled star filled star empty star

Use the animation to help you work out how many lines are needed to draw mystic roses of different sizes.

Pick's Theorem
problem

Pick's theorem

Age
14 to 16
Challenge level
filled star filled star empty star

Polygons drawn on square dotty paper have dots on their perimeter (p) and often internal (i) ones as well. Find a relationship between p, i and the area of the polygons.

Folding in Half
problem

Folding in half

Age
14 to 16
Challenge level
filled star filled star empty star
How does the perimeter change when we fold this isosceles triangle in half?
Contact
problem

Contact

Age
14 to 16
Challenge level
filled star filled star empty star
A circular plate rolls in contact with the sides of a rectangular tray. How much of its circumference comes into contact with the sides of the tray when it rolls around one circuit?
The perforated cube
problem

The perforated cube

Age
14 to 16
Challenge level
filled star empty star empty star
A cube is made from smaller cubes, 5 by 5 by 5, then some of those cubes are removed. Can you make the specified shapes, and what is the most and least number of cubes required ?
Out of the Window
problem

Out of the window

Age
14 to 16
Challenge level
filled star empty star empty star
Find out how many pieces of hardboard of differing sizes can fit through a rectangular window.
Penta Colour
problem

Penta colour

Age
14 to 16
Challenge level
filled star empty star empty star
In how many different ways can I colour the five edges of a pentagon so that no two adjacent edges are the same colour?
Building Gnomons
problem

Building gnomons

Age
14 to 16
Challenge level
filled star empty star empty star
Build gnomons that are related to the Fibonacci sequence and try to explain why this is possible.
Areas of parallelograms
problem

Areas of parallelograms

Age
14 to 16
Challenge level
filled star filled star empty star

Can you find the area of a parallelogram defined by two vectors?

Quadratic Patterns
problem

Quadratic patterns

Age
14 to 16
Challenge level
filled star empty star empty star

Surprising numerical patterns can be explained using algebra and diagrams...

Concrete calculation
problem

Concrete calculation

Age
14 to 16
Challenge level
filled star filled star empty star
The builders have dug a hole in the ground to be filled with concrete for the foundations of our garage. How many cubic metres of ready-mix concrete should the builders order to fill this hole to make the concrete raft for the foundations?
Slick Summing
problem

Slick summing

Age
14 to 16
Challenge level
filled star empty star empty star

Watch the video to see how Charlie works out the sum. Can you adapt his method?

Can you traverse it?
problem

Can you traverse it?

Age
14 to 18
Challenge level
filled star empty star empty star

How can you decide if a graph is traversable?

Corridors
problem

Corridors

Age
14 to 16
Challenge level
filled star filled star empty star
A 10x10x10 cube is made from 27 2x2 cubes with corridors between them. Find the shortest route from one corner to the opposite corner.
Packing Boxes
problem

Packing boxes

Age
14 to 16
Challenge level
filled star filled star empty star
Look at the times that Harry, Christine and Betty take to pack boxes when working in pairs, to find how fast Christine can pack boxes by herself.
Picture Story
problem

Picture story

Age
14 to 16
Challenge level
filled star filled star empty star

Can you see how this picture illustrates the formula for the sum of the first six cube numbers?

Negatively Triangular
problem

Negatively triangular

Age
14 to 16
Challenge level
filled star filled star empty star

How many intersections do you expect from four straight lines ? Which three lines enclose a triangle with negative co-ordinates for every point ?

Bike Shop
problem

Bike shop

Age
14 to 16
Challenge level
filled star filled star empty star
If I walk to the bike shop, but then cycle back, what is my average speed?
Escalator
problem

Escalator

Age
14 to 16
Challenge level
filled star filled star empty star
At Holborn underground station there is a very long escalator. Two people are in a hurry and so climb the escalator as it is moving upwards, thus adding their speed to that of the moving steps. ... How many steps are there on the escalator?
Pythagoras Perimeters
problem

Pythagoras perimeters

Age
14 to 16
Challenge level
filled star filled star empty star

If you know the perimeter of a right angled triangle, what can you say about the area?

Painted Purple
problem

Painted purple

Age
14 to 16
Challenge level
filled star filled star empty star
Three faces of a $3 \times 3$ cube are painted red, and the other three are painted blue. How many of the 27 smaller cubes have at least one red and at least one blue face?
Hexy-Metry
problem

Hexy-metry

Age
14 to 16
Challenge level
filled star filled star filled star

A hexagon, with sides alternately a and b units in length, is inscribed in a circle. How big is the radius of the circle?

Newspaper Sheets
problem

Newspaper sheets

Age
14 to 16
Challenge level
filled star filled star empty star
From only the page numbers on one sheet of newspaper, can you work out how many sheets there are altogether?
Proximity
problem

Proximity

Age
14 to 16
Challenge level
filled star filled star empty star

We are given a regular icosahedron having three red vertices. Show that it has a vertex that has at least two red neighbours.

Bus Stop
problem

Bus stop

Age
14 to 16
Challenge level
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Two buses leave at the same time from two towns Shipton and Veston on the same long road, travelling towards each other. At each mile along the road are milestones. The buses' speeds are constant and in the ratio 5 to 4. The buses travel to and fro between the towns. What milestones are at Shipton and Veston?
Steel Cables
problem

Steel cables

Age
14 to 16
Challenge level
filled star empty star empty star

Some students have been working out the number of strands needed for different sizes of cable. Can you make sense of their solutions?

Geometry and Measure - Short Problems
problem

Tied up

Age
14 to 16
Challenge level
filled star filled star empty star

How much of the field can the animals graze?

Cubic Covering
problem

Cubic covering

Age
14 to 16
Challenge level
filled star filled star empty star
A blue cube has blue cubes glued on all of its faces. Yellow cubes are then glued onto all the visible blue facces. How many yellow cubes are needed?
Tilting Triangles
problem

Tilting triangles

Age
14 to 16
Challenge level
filled star filled star empty star
A right-angled isosceles triangle is rotated about the centre point of a square. What can you say about the area of the part of the square covered by the triangle as it rotates?
Partly Painted Cube
problem

Partly painted cube

Age
14 to 16
Challenge level
filled star filled star empty star

Jo made a cube from some smaller cubes, painted some of the faces of the large cube, and then took it apart again. 45 small cubes had no paint on them at all. How many small cubes did Jo use?