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?
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?
Our 2008 Advent Calendar has a 'Making Maths' activity for every
day in the run-up to Christmas.
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.
Use your mouse to move the red and green parts of this disc. Can
you make images which show the turnings described?
This 100 square jigsaw is written in code. It starts with 1 and ends with 100. Can you build it up?
Sort the houses in my street into different groups. Can you do it in any other ways?
NRICH December 2006 advent calendar - a new tangram for each day in
the run-up to Christmas.
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 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?
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!
An interactive game for 1 person. You are given a rectangle with 50 squares on it. Roll the dice to get a percentage between 2 and 100. How many squares is this? Keep going until you get 100. . . .
An interactive activity for one to experiment with a tricky tessellation
How many different rhythms can you make by putting two drums on the
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!
Place the numbers 1 to 6 in the circles so that each number is the
difference between the two numbers just below it.
Take it in turns to make a triangle on the pegboard. Can you block your opponent?
Can you make a cycle of pairs that add to make a square number
using all the numbers in the box below, once and once only?
Use the interactivity to find out how many quarter turns the man
must rotate through to look like each of the pictures.
An odd version of tic tac toe
A card pairing game involving knowledge of simple ratio.
Choose a symbol to put into the number sentence.
Use the clues to colour each square.
Take it in turns to place a domino on the grid. One to be placed horizontally and the other vertically. Can you make it impossible for your opponent to play?
Choose the size of your pegboard and the shapes you can make. Can you work out the strategies needed to block your opponent?
Use the Cuisenaire rods environment to investigate ratio. Can you
find pairs of rods in the ratio 3:2? How about 9:6?
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.
Move just three of the circles so that the triangle faces in the
Twenty four games for the run-up to Christmas.
Work out the fractions to match the cards with the same amount of
Match the halves.
Start by putting one million (1 000 000) into the display of your
calculator. Can you reduce this to 7 using just the 7 key and add,
subtract, multiply, divide and equals as many times as you like?
How many right angles can you make using two sticks?
Try to stop your opponent from being able to split the piles of counters into unequal numbers. Can you find a strategy?
If you can post the triangle with either the blue or yellow colour face up, how many ways can it be posted altogether?
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?
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?
Use the interactivity to help get a feel for this problem and to find out all the possible ways the balls could land.
Complete the squares - but be warned some are trickier than they
Can you work out how to balance this equaliser? You can put more
than one weight on a hook.
Can you see why 2 by 2 could be 5? Can you predict what 2 by 10
Here are some rods that are different colours. How could I make a dark green rod using yellow and white rods?
What shaped overlaps can you make with two circles which are the
same size? What shapes are 'left over'? What shapes can you make
when the circles are different sizes?
Three beads are threaded on a circular wire and are coloured either red or blue. Can you find all four different combinations?
Can you fit the tangram pieces into the outline of the child walking home from school?
Can you fit the tangram pieces into the outlines of these clocks?
Can you fit the tangram pieces into the outlines of the lobster, yacht and cyclist?