Mr McGregor has a magic potting shed. Overnight, the number of
plants in it doubles. He'd like to put the same number of plants in
each of three gardens, planting one garden each day. Can he do it?
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?
Here is a chance to play a version of the classic Countdown Game.
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?
Arrange the four number cards on the grid, according to the rules,
to make a diagonal, vertical or horizontal line.
In this activity, the computer chooses a times table and shifts it. Can you work out the table and the shift each time?
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?
If you have only four weights, where could you place them in order
to balance this equaliser?
This article gives you a few ideas for understanding the Got It! game and how you might find a winning strategy.
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!
How have the numbers been placed in this Carroll diagram? Which
labels would you put on each row and column?
Can you complete this jigsaw of the multiplication square?
Investigate the smallest number of moves it takes to turn these
mats upside-down if you can only turn exactly three at a time.
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....?
An environment which simulates working with Cuisenaire rods.
Can you see why 2 by 2 could be 5? Can you predict what 2 by 10
A game for two people, or play online. Given a target number, say 23, and a range of numbers to choose from, say 1-4, players take it in turns to add to the running total to hit their target.
Try to stop your opponent from being able to split the piles of counters into unequal numbers. Can you find a strategy?
Imagine a wheel with different markings painted on it at regular
intervals. Can you predict the colour of the 18th mark? The 100th
Try entering different sets of numbers in the number pyramids. How does the total at the top change?
Investigate how the four L-shapes fit together to make an enlarged
L-shape. You could explore this idea with other shapes too.
Our 2008 Advent Calendar has a 'Making Maths' activity for every
day in the run-up to Christmas.
Work out how to light up the single light. What's the rule?
Use the interactivity to find all the different right-angled triangles you can make by just moving one corner of the starting triangle.
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 interactivities to complete these Venn diagrams.
A card pairing game involving knowledge of simple ratio.
Choose a symbol to put into the number sentence.
How can the same pieces of the tangram make this bowl before and after it was chipped? Use the interactivity to try and work out what is going on!
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?
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
Exchange the positions of the two sets of counters in the least possible number of moves
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.
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?
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?
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?
A game for 2 people that everybody knows. You can play with a
friend or online. If you play correctly you never lose!
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?
Try out the lottery that is played in a far-away land. What is the
chance of winning?
Find out what a "fault-free" rectangle is and try to make some of
A generic circular pegboard resource.
Can you find all the different ways of lining up these Cuisenaire
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?
Use the interactivity to create some steady rhythms. How could you
create a rhythm which sounds the same forwards as it does
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.
NRICH December 2006 advent calendar - a new tangram for each day in
the run-up to Christmas.
Identical discs are flipped in the air. You win if all of the faces
show the same colour. Can you calculate the probability of winning
with n discs?