Use the interactivity to help get a feel for this problem and to find out all the possible ways the balls could land.
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.
What happens when you try and fit the triomino pieces into these
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?
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?
Can you cover the camel with these pieces?
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....?
How many trains can you make which are the same length as Matt's, using rods that are identical?
Investigate the smallest number of moves it takes to turn these
mats upside-down if you can only turn exactly three at a time.
Can you find all the different ways of lining up these Cuisenaire
Ben and his mum are planting garlic. Use the interactivity to help
you find out how many cloves of garlic they might have had.
Sort the houses in my street into different groups. Can you do it in any other ways?
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?
Here are some rods that are different colours. How could I make a dark green rod using yellow and white rods?
Use your mouse to move the red and green parts of this disc. Can
you make images which show the turnings described?
How many different triangles can you draw on the dotty grid which each have one dot in the middle?
Explore the different tunes you can make with these five gourds.
What are the similarities and differences between the two tunes you
Place the numbers 1 to 6 in the circles so that each number is the
difference between the two numbers just below it.
Terry and Ali are playing a game with three balls. Is it fair that
Terry wins when the middle ball is red?
Place the numbers 1 to 10 in the circles so that each number is the
difference between the two numbers just below it.
Find out how we can describe the "symmetries" of this triangle and
investigate some combinations of rotating and flipping it.
Can you put the numbers 1 to 8 into the circles so that the four
calculations are correct?
Three beads are threaded on a circular wire and are coloured either red or blue. Can you find all four different combinations?
How many different triangles can you make on a circular pegboard that has nine pegs?
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?
Investigate the different sounds you can make by putting the owls
and donkeys on the wheel.
Cut four triangles from a square as shown in the picture. How many
different shapes can you make by fitting the four triangles back
NRICH December 2006 advent calendar - a new tangram for each day in
the run-up to Christmas.
Can you put the numbers from 1 to 15 on the circles so that no
consecutive numbers lie anywhere along a continuous straight line?
Our 2008 Advent Calendar has a 'Making Maths' activity for every
day in the run-up to Christmas.
How many different ways can you find to join three equilateral triangles together? Can you convince us that you have found them all?
How many triangles can you make using sticks that are 3cm, 4cm and 5cm long?
Can you fit the tangram pieces into the outlines of these clocks?
Can you fit the tangram pieces into the outlines of these people?
Can you fit the tangram pieces into the outline of Little Fung at the table?
Can you fit the tangram pieces into the outline of this brazier for roasting chestnuts?
An interactive game to be played on your own or with friends.
Imagine you are having a party. Each person takes it in turns to
stand behind the chair where they will get the most chocolate.
Can you fit the tangram pieces into the outline of this telephone?
A game for 2 people that can be played on line or with pens and paper. Combine your knowledege of coordinates with your skills of strategic thinking.
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?
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?
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?
Starting with the number 180, take away 9 again and again, joining up the dots as you go. Watch out - don't join all the dots!
Make one big triangle so the numbers that touch on the small triangles add to 10. You could use the interactivity to help you.
A game for 2 people that everybody knows. You can play with a
friend or online. If you play correctly you never lose!
Exchange the positions of the two sets of counters in the least possible number of moves
Can you fit the tangram pieces into the outlines of the chairs?
Can you fit the tangram pieces into the outlines of the lobster, yacht and cyclist?