Choose four of the numbers from 1 to 9 to put in the squares so that the differences between joined squares are odd.
Choose a symbol to put into the number sentence.
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?
Use the information about Sally and her brother to find out how many children there are in the Brown family.
Can you hang weights in the right place to make the equaliser balance?
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?
If you have only four weights, where could you place them in order to balance this equaliser?
Place the numbers 1 to 10 in the circles so that each number is the difference between the two numbers just below it.
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!
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?
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?
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....?
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?
Can you see why 2 by 2 could be 5? Can you predict what 2 by 10 will be?
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 work out how to balance this equaliser? You can put more than one weight on a hook.
Place six toy ladybirds into the box so that there are two ladybirds in every column and every row.
Have a go at this well-known challenge. Can you swap the frogs and toads in as few slides and jumps as possible?
Can you put the numbers 1 to 8 into the circles so that the four calculations are correct?
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 happens when you try and fit the triomino pieces into these two grids?
Use the number weights to find different ways of balancing the equaliser.
Try to stop your opponent from being able to split the piles of counters into unequal numbers. Can you find a strategy?
Can you cover the camel with these pieces?
Here are some rods that are different colours. How could I make a dark green rod using yellow and white rods?
How many different rhythms can you make by putting two drums on the wheel?
Investigate the smallest number of moves it takes to turn these mats upside-down if you can only turn exactly three at a time.
Use the interactivity to find all the different right-angled triangles you can make by just moving one corner of the starting triangle.
An odd version of tic tac toe
Can you complete this jigsaw of the multiplication square?
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 make a train the same length as Laura's but using three differently coloured rods? Is there only one way of doing it?
Can you make the green spot travel through the tube by moving the yellow spot? Could you draw a tube that both spots would follow?
Try out the lottery that is played in a far-away land. What is the chance of winning?
A variant on the game Alquerque
Move just three of the circles so that the triangle faces in the opposite direction.
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?
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 find all the different ways of lining up these Cuisenaire rods?
Use the clues to colour each square.
Here is a chance to play a version of the classic Countdown Game.
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?
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.
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?
Twenty four games for the run-up to Christmas.
Can you put the numbers from 1 to 15 on the circles so that no consecutive numbers lie anywhere along a continuous straight line?
Arrange the four number cards on the grid, according to the rules, to make a diagonal, vertical or horizontal line.