Filter by: Content type: ALL Problems Articles Games Stage: All Stage 1&2 Stage 2&3 Stage 3&4 Stage 4&5 Challenge level:
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?
Place the numbers 1 to 10 in the circles so that each number is the difference between the two numbers just below it.
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 in them?
Have a go at this well-known challenge. Can you swap the frogs and toads in as few slides and jumps as possible?
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 numbers from 1 to 15 on the circles so that no consecutive numbers lie anywhere along a continuous straight line?
What do the numbers shaded in blue on this hundred square have in common? What do you notice about the pink numbers? How about the shaded numbers in the other squares?
Can you find all the different ways of lining up these Cuisenaire rods?
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 different triangles can you make on a circular pegboard that has nine pegs?
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 interactivity to find all the different right-angled triangles you can make by just moving one corner of the starting triangle.
Investigate the smallest number of moves it takes to turn these mats upside-down if you can only turn exactly three at a time.
This 100 square jigsaw is written in code. It starts with 1 and ends with 100. Can you build it up?
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 put the numbers 1 to 8 into the circles so that the four calculations are correct?
Cut four triangles from a square as shown in the picture. How many different shapes can you make by fitting the four triangles back together?
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?
An environment which simulates working with Cuisenaire rods.
Choose a symbol to put into the number sentence.
Find out how we can describe the "symmetries" of this triangle and investigate some combinations of rotating and flipping it.
Our 2008 Advent Calendar has a 'Making Maths' activity for every day in the run-up to Christmas.
Find out what a "fault-free" rectangle is and try to make some of your own.
Three beads are threaded on a circular wire and are coloured either red or blue. Can you find all four different combinations?
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?
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?
Try out the lottery that is played in a far-away land. What is the chance of winning?
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!
Can you find all the different triangles on these peg boards, and find their angles?
Explore the different tunes you can make with these five gourds. What are the similarities and differences between the two tunes you are given?
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?
NRICH December 2006 advent calendar - a new tangram for each day in the run-up to Christmas.
Arrange the four number cards on the grid, according to the rules, to make a diagonal, vertical or horizontal line.
Can you see why 2 by 2 could be 5? Can you predict what 2 by 10 will be?
Can you fit the tangram pieces into the outline of this brazier for roasting chestnuts?
Can you fit the tangram pieces into the outlines of these people?
An interactive activity for one to experiment with a tricky tessellation
Can you fit the tangram pieces into the outlines of the lobster, yacht and cyclist?
Can you complete this jigsaw of the multiplication square?
A train building game for 2 players.
Can you fit the tangram pieces into the outlines of these clocks?
A game for 2 people that everybody knows. You can play with a friend or online. If you play correctly you never lose!
Can you fit the tangram pieces into the outline of the child walking home from school?
A card pairing game involving knowledge of simple ratio.
Can you fit the tangram pieces into the outline of Granma T?
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?
You have 27 small cubes, 3 each of nine colours. Use the small cubes to make a 3 by 3 by 3 cube so that each face of the bigger cube contains one of every colour.
Place the numbers from 1 to 9 in the squares below so that the difference between joined squares is odd. How many different ways can you do this?
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 the sightings of the lion to guess the location of its lair.