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.
Use the interactivities to fill in these Carroll diagrams. How do you know where to place the numbers?
How have the numbers been placed in this Carroll diagram? Which
labels would you put on each row and column?
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!
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?
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?
This article gives you a few ideas for understanding the Got It! game and how you might find a winning strategy.
Investigate which numbers make these lights come on. What is the smallest number you can find that lights up all the lights?
Choose four of the numbers from 1 to 9 to put in the squares so that the differences between joined squares are odd.
Try to stop your opponent from being able to split the piles of counters into unequal numbers. Can you find a strategy?
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?
Mr Gilderdale is playing a game with his class. What rule might he have chosen? How would you test your idea?
The idea of this game is to add or subtract the two numbers on the
dice and cover the result on the grid, trying to get a line of
three. Are there some numbers that are good to aim for?
An environment which simulates working with Cuisenaire rods.
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?
Ben and his mum are planting garlic. Use the interactivity to help
you find out how many cloves of garlic they might have had.
Can you see why 2 by 2 could be 5? Can you predict what 2 by 10
Can you hang weights in the right place to make the equaliser
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 complete this jigsaw of the multiplication square?
Use the number weights to find different ways of balancing the equaliser.
If you have only four weights, where could you place them in order
to balance this equaliser?
An odd version of tic tac toe
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....?
Match the halves.
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 find out how many quarter turns the man
must rotate through to look like each of the pictures.
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?
A card pairing game involving knowledge of simple ratio.
Imagine a wheel with different markings painted on it at regular
intervals. Can you predict the colour of the 18th mark? The 100th
A variant on the game Alquerque
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 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. . . .
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.
A game for 1 or 2 people. Use the interactive version, or play with friends. Try to round up as many counters as possible.
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.
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.
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?
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?
Move just three of the circles so that the triangle faces in the
Use the information about Sally and her brother to find out how many children there are in the Brown family.
Yasmin and Zach have some bears to share. Which numbers of bears
can they share so that there are none left over?
Make one big triangle so the numbers that touch on the small triangles add to 10. You could use the interactivity to help you.
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?
Arrange the four number cards on the grid, according to the rules,
to make a diagonal, vertical or horizontal line.
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?
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