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?
Place the numbers 1 to 10 in the circles so that each number is the
difference between the two numbers just below it.
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?
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?
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?
Investigate the smallest number of moves it takes to turn these
mats upside-down if you can only turn exactly three at a time.
Have a go at this well-known challenge. Can you swap the frogs and toads in as few slides and jumps as possible?
Choose four of the numbers from 1 to 9 to put in the squares so that the differences between joined squares are odd.
This 100 square jigsaw is written in code. It starts with 1 and ends with 100. Can you build it up?
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?
Place six toy ladybirds into the box so that there are two ladybirds in every column and every row.
If you have only four weights, where could you place them in order
to balance this equaliser?
Place the numbers 1 to 6 in the circles so that each number is the
difference between the two numbers just below it.
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?
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 1 to 8 into the circles so that the four
calculations are correct?
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!
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....?
What happens when you try and fit the triomino pieces into these
How many trains can you make which are the same length as Matt's, using rods that are identical?
An environment which simulates working with Cuisenaire rods.
Can you hang weights in the right place to make the equaliser
Can you use the numbers on the dice to reach your end of the number line before your partner beats you?
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 information about Sally and her brother to find out how many children there are in the Brown family.
Can you see why 2 by 2 could be 5? Can you predict what 2 by 10
Make one big triangle so the numbers that touch on the small triangles add to 10. You could use the interactivity to help you.
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?
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?
Use the interactivity to find all the different right-angled
triangles you can make by just moving one corner of the starting
Can you work out how to balance this equaliser? You can put more
than one weight on a hook.
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 complete this jigsaw of the multiplication square?
An odd version of tic tac toe
Can you cover the camel with these pieces?
Can you find all the different ways of lining up these Cuisenaire
Choose a symbol to put into the number sentence.
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?
Here is a chance to play a version of the classic Countdown Game.
Investigate which numbers make these lights come on. What is the smallest number you can find that lights up all the lights?
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?
Can you put the numbers from 1 to 15 on the circles so that no
consecutive numbers lie anywhere along a continuous straight line?
Try out the lottery that is played in a far-away land. What is the
chance of winning?
Use the clues to colour each square.
Use the number weights to find different ways of balancing the equaliser.
Here are some rods that are different colours. How could I make a dark green rod using yellow and white rods?
Use the interactivity to sort these numbers into sets. Can you give
each set a name?
First Connect Three game for an adult and child. Use the dice numbers and either addition or subtraction to get three numbers in a straight line.
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?