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?
NRICH December 2006 advent calendar - a new tangram for each day in
the run-up to Christmas.
Investigate the smallest number of moves it takes to turn these
mats upside-down if you can only turn exactly three at a time.
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 trains can you make which are the same length as Matt's,
using rods that are identical?
Can you work out how to balance this equaliser? You can put more
than one weight on a hook.
Can you cover the camel with these pieces?
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
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!
An environment which simulates working with Cuisenaire rods.
What happens when you try and fit the triomino pieces into these
Arrange the four number cards on the grid, according to the rules,
to make a diagonal, vertical or horizontal line.
Can you put the numbers from 1 to 15 on the circles so that no
consecutive numbers lie anywhere along a continuous straight line?
Place six toy ladybirds into the box so that there are two
ladybirds in every column and every row.
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.
Use the clues to colour each square.
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 complete this jigsaw of the multiplication square?
Can you put the numbers 1 to 8 into the circles so that the four
calculations are correct?
If you have only four weights, where could you place them in order
to balance this equaliser?
Ben and his mum are planting garlic. Use the interactivity to help
you find out how many cloves of garlic they might have had.
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?
How many different rhythms can you make by putting two drums on the
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!
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?
Here is a chance to play a version of the classic Countdown Game.
A generic circular pegboard resource.
Choose 13 spots on the grid. Can you work out the scoring system? What is the maximum possible score?
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?
Use the interactivity to find out how many quarter turns the man
must rotate through to look like each of the pictures.
Choose four of the numbers from 1 to 9 to put in the squares so that the differences between joined squares are odd.
How many different triangles can you make on a circular pegboard that has nine pegs?
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?
Make one big triangle so the numbers that touch on the small triangles add to 10. You could use the interactivity to help you.
An interactive activity for one to experiment with a tricky tessellation
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?
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?
Three beads are threaded on a circular wire and are coloured either red or blue. Can you find all four different combinations?
Complete the squares - but be warned some are trickier than they
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?
Use the interactivity to help get a feel for this problem and to find out all the possible ways the balls could land.
Explore the different tunes you can make with these five gourds.
What are the similarities and differences between the two tunes you
Choose a symbol to put into the number sentence.
Can you find all the different ways of lining up these Cuisenaire
A train building game for 2 players.
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 make a cycle of pairs that add to make a square number
using all the numbers in the box below, once and once only?
This 100 square jigsaw is written in code. It starts with 1 and ends with 100. Can you build it up?