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?
How many different rhythms can you make by putting two drums on the
What happens when you try and fit the triomino pieces into these
Can you cover the camel with these pieces?
How many different triangles can you draw on the dotty grid which each have one dot in the middle?
Sort the houses in my street into different groups. Can you do it in any other ways?
This 100 square jigsaw is written in code. It starts with 1 and
ends with 100. Can you build it up?
How many triangles can you make using sticks that are 3cm, 4cm and 5cm long?
Three beads are threaded on a circular wire and are coloured either red or blue. Can you find all four different combinations?
Investigate the smallest number of moves it takes to turn these
mats upside-down if you can only turn exactly three at a time.
How many different ways can you find to join three equilateral
triangles together? Can you convince us that you have found them
How many different triangles can you make on a circular pegboard
that has nine pegs?
Have a go at this well-known challenge. Can you swap the frogs and toads in as few slides and jumps as possible?
Find out how we can describe the "symmetries" of this triangle and
investigate some combinations of rotating and flipping it.
Use your mouse to move the red and green parts of this disc. Can
you make images which show the turnings described?
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?
Ben and his mum are planting garlic. Use the interactivity to help
you find out how many cloves of garlic they might have had.
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
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?
NRICH December 2006 advent calendar - a new tangram for each day in
the run-up to Christmas.
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?
Cut four triangles from a square as shown in the picture. How many
different shapes can you make by fitting the four triangles back
Can you work out how to balance this equaliser? You can put more
than one weight on a hook.
Place six toy ladybirds into the box so that there are two
ladybirds in every column and every row.
How many trains can you make which are the same length as Matt's,
using rods that are identical?
Use the clues to colour each square.
Here are some rods that are different colours. How could I make a dark green rod using yellow and white rods?
Use the interactivity to help get a feel for this problem and to find out all the possible ways the balls could land.
Place the numbers 1 to 6 in the circles so that each number is the
difference between the two numbers just below it.
Our 2008 Advent Calendar has a 'Making Maths' activity for every
day in the run-up to Christmas.
Can you find all the different ways of lining up these Cuisenaire
Arrange the four number cards on the grid, according to the rules,
to make a diagonal, vertical or horizontal line.
Find out what a "fault-free" rectangle is and try to make some of
This problem is based on a code using two different prime numbers
less than 10. You'll need to multiply them together and shift the
alphabet forwards by the result. Can you decipher the code?
Can you make a train the same length as Laura's but using three
differently coloured rods? Is there only one way of doing it?
Complete the squares - but be warned some are trickier than they
Place the numbers 1 to 10 in the circles so that each number is the
difference between the two numbers just below it.
A game for 2 people that everybody knows. You can play with a
friend or online. If you play correctly you never lose!
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 train building game for 2 players.
Make one big triangle so the numbers that touch on the small triangles add to 10. You could use the interactivity to help you.
Move just three of the circles so that the triangle faces in the
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?
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?
Twenty four games for the run-up to Christmas.
In your bank, you have three types of coins. The number of spots shows how much they are worth. Can you choose coins to exchange with the groups given to make the same total?
An interactive activity for one to experiment with a tricky tessellation
Take it in turns to make a triangle on the pegboard. Can you block
A game to be played against the computer, or in groups. Pick a 7-digit number. A random digit is generated. What must you subract to remove the digit from your number? the first to zero wins.