![The Best Card Trick?](/sites/default/files/styles/medium/public/thumbnails/content-03-03-art3-icon.gif?itok=G0dgCNfY)
problem
The Best Card Trick?
Time for a little mathemagic! Choose any five cards from a pack and show four of them to your partner. How can they work out the fifth?
![Take Three From Five](/sites/default/files/styles/medium/public/thumbnails/content-03-10-six3-icon.png?itok=W75fA1WM)
problem
Take Three From Five
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?
![Cyclic Quad Jigsaw](/sites/default/files/styles/medium/public/thumbnails/content-00-06-six6-icon.gif?itok=93IJnDPt)
problem
Cyclic Quad Jigsaw
A picture is made by joining five small quadrilaterals together to
make a large quadrilateral. Is it possible to draw a similar
picture if all the small quadrilaterals are cyclic?
![Amazing Card Trick](/sites/default/files/styles/medium/public/thumbnails/content-03-12-six5-icon.gif?itok=FxCzlw8G)
![Seven Squares - Group-worthy Task](/sites/default/files/styles/medium/public/thumbnails/content-id-2290-icon.png?itok=onTztJr5)
problem
Seven Squares - Group-worthy Task
Choose a couple of the sequences. Try to picture how to make the next, and the next, and the next... Can you describe your reasoning?
![Factorising with Multilink](/sites/default/files/styles/medium/public/thumbnails/content-id-7490-icon.png?itok=JmNdK-Pw)
problem
Factorising with Multilink
Can you find out what is special about the dimensions of rectangles you can make with squares, sticks and units?
![Always a multiple?](/sites/default/files/styles/medium/public/thumbnails/content-id-7208-icon.png?itok=fjSKmic9)
problem
Always a multiple?
Think of a two digit number, reverse the digits, and add the numbers together. Something special happens...
![Whirlyball](/sites/default/files/styles/medium/public/thumbnails/content-id-4756-icon.jpg?itok=RWIlrEU4)
problem
Whirlyball
Whirl a conker around in a horizontal circle on a piece of string.
What is the smallest angular speed with which it can whirl?
![Method in multiplying madness?](/sites/default/files/styles/medium/public/thumbnails/content-id-5612-icon.png?itok=ZHpntMLH)
problem
Method in multiplying madness?
Watch our videos of multiplication methods that you may not have met before. Can you make sense of them?
![Symmetric Tangles](/sites/default/files/styles/medium/public/thumbnails/content-id-5746-icon.jpg?itok=r8ngRfHK)
article
Symmetric Tangles
The tangles created by the twists and turns of the Conway rope
trick are surprisingly symmetrical. Here's why!
![ACE, TWO, THREE...](/sites/default/files/styles/medium/public/thumbnails/content-id-5775-icon.png?itok=fWWWcW02)
problem
ACE, TWO, THREE...
Can you picture how to order the cards to reproduce Charlie's card trick for yourself?
![Twisting and Turning](/sites/default/files/styles/medium/public/thumbnails/content-id-5776-icon.jpg?itok=piqO4PnB)
problem
Twisting and Turning
Take a look at the video and try to find a sequence of moves that will untangle the ropes.
![The Invertible Trefoil](/sites/default/files/styles/medium/public/thumbnails/content-id-5861-icon.png?itok=dSFXuxAX)
![Impossible square?](/sites/default/files/styles/medium/public/thumbnails/content-id-5869-icon.jpg?itok=bRxBTuHL)
![Impossible triangles?](/sites/default/files/styles/medium/public/thumbnails/content-id-5923-icon.jpg?itok=85LFUqIZ)
![Galley Division](/sites/default/files/styles/medium/public/thumbnails/content-id-6276-icon.png?itok=6HDho0kF)
![Strike it Out](/sites/default/files/styles/medium/public/thumbnails/content-id-6589-icon.gif?itok=PtQ_v8tW)
problem
Strike it Out
Use your addition and subtraction skills, combined with some strategic thinking, to beat your partner at this game.
![Speedy summations](/sites/default/files/styles/medium/public/thumbnails/content-id-6610-icon.jpg?itok=sz31K0yv)
problem
Speedy summations
Watch the video to see how to add together an arithmetic sequence of numbers efficiently.
![Slick Summing](/sites/default/files/styles/medium/public/thumbnails/content-id-6710-icon.jpg?itok=XiU2im4-)
problem
Slick Summing
Watch the video to see how Charlie works out the sum. Can you adapt his method?
![Modular origami polyhedra](/sites/default/files/styles/medium/public/thumbnails/modular-origami-polyhedra.jpg?itok=6f0lTKMW)
page
Modular origami polyhedra
These models have appeared around the Centre for Mathematical Sciences. Perhaps you would like to try to make some similar models of your own.
![Kingsfield School - Building on Rich Starting Points](/sites/default/files/styles/medium/public/thumbnails/content-id-6808-icon.png?itok=8jjXG3Yb)
article
Kingsfield School - Building on Rich Starting Points
Alf and Tracy explain how the Kingsfield School maths department use common tasks to encourage all students to think mathematically about key areas in the curriculum.
![Drawing Celtic Knots](/sites/default/files/styles/medium/public/thumbnails/content-id-6809-icon.gif?itok=Ww25gaqM)
problem
Drawing Celtic Knots
Here is a chance to create some Celtic knots and explore the mathematics behind them.
![Turning the Place Over](/sites/default/files/styles/medium/public/thumbnails/turning-the-place-over.jpg?itok=dOui8U_T)
page
Turning the Place Over
As part of Liverpool08 European Capital of Culture there were a
huge number of events and displays. One of the art installations
was called "Turning the Place Over". Can you find our how it works?
![Placeholder: several colourful numbers](/themes/nrich/images/nrich_small_placeholder.png)
project
How Many?
This project challenges you to work out the number of cubes hidden under a cloth. What questions would you like to ask?
![Placeholder: several colourful numbers](/themes/nrich/images/nrich_small_placeholder.png)
page
Jo Boaler explains Complex Instruction
A video clip of Jo Boaler talking about Complex Instruction.
![Dotty Six](/sites/default/files/styles/medium/public/thumbnails/content-id-7337-icon.png?itok=8RBr3_y9)
![Bryony's Triangle](/sites/default/files/styles/medium/public/thumbnails/content-id-7392-icon.jpg?itok=L3-YhaCi)
problem
Bryony's Triangle
Watch the video to see how to fold a square of paper to create a flower. What fraction of the piece of paper is the small triangle?
![Take one example](/sites/default/files/styles/medium/public/thumbnails/content-id-8081-icon.png?itok=Qgy-UHis)
article
Take one example
This article introduces the idea of generic proof for younger children and illustrates how one example can offer a proof of a general result through unpacking its underlying structure.
![Constructing Triangles](/sites/default/files/styles/medium/public/thumbnails/content-id-8098-icon.png?itok=2JGN3wZM)
problem
Constructing Triangles
Generate three random numbers to determine the side lengths of a triangle. What triangles can you draw?