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.
Investigate which numbers make these lights come on. What is the smallest number you can find that lights up all the lights?
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?
Can you use the numbers on the dice to reach your end of the number line before your partner beats you?
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?
Can you complete this jigsaw of the 100 square?
Can you complete this jigsaw of the multiplication square?
An odd version of tic tac toe
A game for 2 people that everybody knows. You can play with a
friend or online. If you play correctly you never lose!
Choose four of the numbers from 1 to 9 to put in the squares so
that the differences between joined squares are odd.
Use the interactivities to complete these Venn diagrams.
Investigate the smallest number of moves it takes to turn these
mats upside-down if you can only turn exactly three at a time.
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?
Mr Gilderdale is playing a game with his class. What rule might he have chosen? How would you test your idea?
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....?
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?
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?
There are three versions of this challenge. The idea is to change the colour of all the spots on the grid. Can you do it in fewer throws of the dice?
You'll need two dice to play this game against a partner. Will Incey Wincey make it to the top of the drain pipe or the bottom of the drain pipe first?
Can you put the numbers from 1 to 15 on the circles so that no
consecutive numbers lie anywhere along a continuous straight line?
Can you hang weights in the right place to make the equaliser
Try to stop your opponent from being able to split the piles of counters into unequal numbers. Can you find a strategy?
Use the number weights to find different ways of balancing the equaliser.
An interactive game to be played on your own or with friends.
Imagine you are having a party. Each person takes it in turns to
stand behind the chair where they will get the most chocolate.
Play a dice game of chance
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?
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?
Use the information about Sally and her brother to find out how many children there are in the Brown family.
Three beads are threaded on a circular wire and are coloured either red or blue. Can you find all four different combinations?
How many triangles can you make using sticks that are 3cm, 4cm and 5cm long?
A variant on the game Alquerque
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
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?
Arrange the four number cards on the grid, according to the rules,
to make a diagonal, vertical or horizontal line.
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?
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.
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!
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?
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.
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.
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. . . .
Yasmin and Zach have some bears to share. Which numbers of bears
can they share so that there are none left over?
How many different rhythms can you make by putting two drums on the
A game for 1 person. Can you work out how the dice must be rolled from the start position to the finish? Play on line.
Can you beat Piggy in this simple dice game? Can you figure out
Piggy's strategy, and is there a better one?