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?
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?
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?
Arrange the four number cards on the grid, according to the rules,
to make a diagonal, vertical or horizontal line.
Have a go at this well-known challenge. Can you swap the frogs and toads in as few slides and jumps as possible?
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?
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!
If you hang two weights on one side of this balance, in how many different ways can you hang three weights on the other side for it to be balanced?
Place the numbers 1 to 10 in the circles so that each number is the
difference between the two numbers just below it.
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.
Can you see why 2 by 2 could be 5? Can you predict what 2 by 10
Can you find all the different ways of lining up these Cuisenaire
Choose four of the numbers from 1 to 9 to put in the squares so that the differences between joined squares are odd.
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 use the numbers on the dice to reach your end of the number line before your partner beats you?
How many trains can you make which are the same length as Matt's, using rods that are identical?
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?
How have the numbers been placed in this Carroll diagram? Which
labels would you put on each row and column?
Use the interactivities to fill in these Carroll diagrams. How do you know where to place the numbers?
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?
Use the interactivity to find all the different right-angled
triangles you can make by just moving one corner of the starting
Use the clues to colour each square.
Can you hang weights in the right place to make the equaliser
What happens when you try and fit the triomino pieces into these
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?
Here is a chance to play a version of the classic Countdown Game.
Try out the lottery that is played in a far-away land. What is the
chance of winning?
Can you put the numbers from 1 to 15 on the circles so that no
consecutive numbers lie anywhere along a continuous straight line?
Use the number weights to find different ways of balancing the 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.
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.
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....?
Use the information about Sally and her brother to find out how many children there are in the Brown family.
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?
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?
This 100 square jigsaw is written in code. It starts with 1 and ends with 100. Can you build it up?
Choose a symbol to put into the number sentence.
Imagine a wheel with different markings painted on it at regular
intervals. Can you predict the colour of the 18th mark? The 100th
Use your mouse to move the red and green parts of this disc. Can
you make images which show the turnings described?
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.
How many triangles can you make using sticks that are 3cm, 4cm and 5cm long?
An odd version of tic tac toe
How many different rhythms can you make by putting two drums on the
Move just three of the circles so that the triangle faces in the
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?