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'.
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.
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?
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?
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?

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?
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.

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?

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?

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?

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?

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.

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?

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.

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?
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.
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 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?
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?

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
filled star filled star empty star
Here's a neat trick you can do with an 11 by 11 square...
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?

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.

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.
Multiple Surprises
problem

Multiple surprises

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

Sequences of multiples keep cropping up...

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?

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.
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.

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.
Pythagoras Proofs
problem

Pythagoras proofs

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

Can you make sense of these three proofs of Pythagoras' Theorem?

Placeholder: several colourful numbers
problem

Bent out of shape

Age
14 to 18
Challenge level
filled star filled star empty star
An introduction to bond angle geometry.
Gnomon dimensions
problem

Gnomon dimensions

Age
14 to 16
Challenge level
filled star filled star empty star
These gnomons appear to have more than a passing connection with the Fibonacci sequence. This problem ask you to investigate some of these connections.
Dicey Directions
problem

Dicey directions

Age
14 to 16
Challenge level
filled star empty star empty star
An ordinary die is placed on a horizontal table with the '1' face facing East... In which direction is the '1' face facing after this sequence of moves?
Relative Time
problem

Relative time

Age
14 to 16
Challenge level
filled star filled star empty star
Albert Einstein is experimenting with two unusual clocks. At what time do they next agree?
Vector walk
problem

Vector walk

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

Starting with two basic vector steps, which destinations can you reach on a vector walk?

Isosceles Seven
problem

Isosceles seven

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

Is it possible to find the angles in this rather special isosceles triangle?

The Spider and the Fly
problem

The spider and the fly

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

A spider is sitting in the middle of one of the smallest walls in a room and a fly is resting beside the window. What is the shortest distance the spider would have to crawl to catch the fly?

Fermat's Poser
problem

Fermat's poser

Age
14 to 16
Challenge level
filled star filled star filled star
Find the point whose sum of distances from the vertices (corners) of a given triangle is a minimum.
Triangles within Triangles
problem

Triangles within triangles

Age
14 to 16
Challenge level
filled star empty star empty star
Can you find a rule which connects consecutive triangular numbers?
Vector journeys
problem

Vector journeys

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

Charlie likes to go for walks around a square park, while Alison likes to cut across diagonally. Can you find relationships between the vectors they walk along?

Partly Circles
problem

Partly circles

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

What is the same and what is different about these circle questions? What connections can you make?

Eulerian
problem

Eulerian

Age
14 to 16
Challenge level
filled star empty star empty star
Weekly Problem 37 - 2014
Which of the five diagrams below could be drawn without taking the pen off the page and without drawing along a line already drawn?
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?

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?
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?
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?
Factorising with Multilink
problem

Factorising with multilink

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

Can you find out what is special about the dimensions of rectangles you can make with squares, sticks and units?

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?

Pyramidal n-gon
problem

Pyramidal n-gon

Age
14 to 16
Challenge level
filled star filled star empty star
The base of a pyramid has n edges. What is the difference between the number of edges the pyramid has and the number of faces the pyramid has?
Summing squares
problem

Summing squares

Age
14 to 16
Challenge level
filled star filled star empty star
Discover a way to sum square numbers by building cuboids from small cubes. Can you picture how the sequence will grow?
Semicircular Design
problem

Semicircular design

Age
14 to 16
Challenge level
filled star empty star empty star
Weekly Problem 9 - 2016
The diagram to the right shows a logo made from semi-circular arcs. What fraction of the logo is shaded?
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.

Curve Hunter
problem

Curve hunter

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

This problem challenges you to sketch curves with different properties.

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?
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.
Fill Me Up Too
problem

Fill me up too

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

In Fill Me Up we invited you to sketch graphs as vessels are filled with water. Can you work out the equations of the graphs?

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.
A question of scale
problem

A question of scale

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

Use your skill and knowledge to place various scientific lengths in order of size. Can you judge the length of objects with sizes ranging from 1 Angstrom to 1 million km with no wrong attempts?

In or Out?
problem

In or out?

Age
14 to 16
Challenge level
filled star filled star filled star
Weekly Problem 52 - 2014
Four arcs are drawn in a circle to create a shaded area. What fraction of the area of the circle is shaded?
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.

Travelling by Train
problem

Travelling by train

Age
14 to 16
Challenge level
filled star filled star empty star
Stephen stops at Darlington on his way to Durham. At what time does he arrive at Durham?
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?
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.
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.
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?

Spotting the loophole
problem

Spotting the loophole

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

A visualisation problem in which you search for vectors which sum to zero from a jumble of arrows. Will your eyes be quicker than algebra?

What's that graph?
problem

What's that graph?

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

Can you work out which processes are represented by the graphs?

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?
Trisected Triangle
problem

Trisected triangle

Age
14 to 16
Challenge level
filled star filled star empty star
Weekly Problem 34 - 2015
Four tiles are given. For which of them can three be placed together to form an equilateral triangle?
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.
Oldest and Youngest
problem

Oldest and youngest

Age
14 to 16
Challenge level
filled star filled star empty star
Edith had 9 children at 15 month intervals. If the oldest is now six times as old as the youngest, how old is her youngest child?
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?

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?
Five coloured cubes forming the edges of a pentagon.
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?

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?

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?
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?

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?

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?

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?

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?
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
filled star filled star filled star
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?
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?
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?