Use your mouse to move the red and green parts of this disc. Can
you make images which show the turnings described?
Find out how we can describe the "symmetries" of this triangle and
investigate some combinations of rotating and flipping it.
How many different triangles can you make on a circular pegboard
that has nine pegs?
You have 4 red and 5 blue counters. How many ways can they be
placed on a 3 by 3 grid so that all the rows columns and diagonals
have an even number of red counters?
Can you cover the camel with these pieces?
What happens when you try and fit the triomino pieces into these
How many different triangles can you draw on the dotty grid which each have one dot in the middle?
Can you sort these triangles into three different families and explain how you did it?
This was a problem for our birthday website. Can you use four of these pieces to form a square? How about making a square with all five pieces?
What does the overlap of these two shapes look like? Try picturing
it in your head and then use the interactivity to test your
A tetromino is made up of four squares joined edge to edge. Can
this tetromino, together with 15 copies of itself, be used to cover
an eight by eight chessboard?
Can you put the 25 coloured tiles into the 5 x 5 square so that no
column, no row and no diagonal line have tiles of the same colour
Can you work out how to balance this equaliser? You can put more
than one weight on a hook.
Use the clues to colour each square.
Our 2008 Advent Calendar has a 'Making Maths' activity for every
day in the run-up to Christmas.
Use the interactivity to help get a feel for this problem and to find out all the possible ways the balls could land.
Here are some rods that are different colours. How could I make a dark green rod using yellow and white rods?
How many triangles can you make using sticks that are 3cm, 4cm and 5cm long?
How many different rhythms can you make by putting two drums on the
Hover your mouse over the counters to see which ones will be
removed. Click to remover them. The winner is the last one to
remove a counter. How you can make sure you win?
Three beads are threaded on a circular wire and are coloured either red or blue. Can you find all four different combinations?
Sort the houses in my street into different groups. Can you do it in any other ways?
Take it in turns to make a triangle on the pegboard. Can you block
NRICH December 2006 advent calendar - a new tangram for each day in
the run-up to Christmas.
Cut four triangles from a square as shown in the picture. How many
different shapes can you make by fitting the four triangles back
Move just three of the circles so that the triangle faces in the
Ahmed has some wooden planks to use for three sides of a rabbit run
against the shed. What quadrilaterals would he be able to make with
the planks of different lengths?
Place six toy ladybirds into the box so that there are two
ladybirds in every column and every row.
Can you put the numbers 1 to 8 into the circles so that the four
calculations are correct?
What are the coordinates of the coloured dots that mark out the
tangram? Try changing the position of the origin. What happens to
the coordinates now?
A game for 2 people that everybody knows. You can play with a
friend or online. If you play correctly you never lose!
Match the halves.
If there are 3 squares in the ring, can you place three different numbers in them so that their differences are odd? Try with different numbers of squares around the ring. What do you notice?
Can you fit the tangram pieces into the outlines of the workmen?
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?
Explore the different tunes you can make with these five gourds.
What are the similarities and differences between the two tunes you
A generic circular pegboard resource.
Can you make the green spot travel through the tube by moving the
yellow spot? Could you draw a tube that both spots would follow?
Investigate the different sounds you can make by putting the owls
and donkeys on the wheel.
Using angular.js to bind inputs to outputs
Can you put the numbers from 1 to 15 on the circles so that no
consecutive numbers lie anywhere along a continuous straight line?
Choose the size of your pegboard and the shapes you can make. Can
you work out the strategies needed to block your opponent?
Place the numbers 1 to 6 in the circles so that each number is the
difference between the two numbers just below it.
Use the Cuisenaire rods environment to investigate ratio. Can you
find pairs of rods in the ratio 3:2? How about 9:6?
Can you find all the different triangles on these peg boards, and
find their angles?
Work out the fractions to match the cards with the same amount of
Is it possible to place 2 counters on the 3 by 3 grid so that there
is an even number of counters in every row and every column? How
about if you have 3 counters or 4 counters or....?
Can you fit the tangram pieces into the outlines of these people?
Can you fit the tangram pieces into the outlines of these clocks?
Can you fit the tangram pieces into the outline of the child walking home from school?