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.
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?
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?
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?
An environment which simulates working with Cuisenaire rods.
If you have only four weights, where could you place them in order
to balance this equaliser?
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!
Place the numbers 1 to 6 in the circles so that each number is the
difference between the two numbers just below it.
Use the information about Sally and her brother to find out how many children there are in the Brown family.
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.
Here is a chance to play a version of the classic Countdown Game.
Can you use the numbers on the dice to reach your end of the number line before your partner beats you?
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?
Use the clues to colour each square.
Can you see why 2 by 2 could be 5? Can you predict what 2 by 10
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?
Investigate the smallest number of moves it takes to turn these
mats upside-down if you can only turn exactly three at a time.
Ben and his mum are planting garlic. Use the interactivity to help
you find out how many cloves of garlic they might have had.
How have the numbers been placed in this Carroll diagram? Which
labels would you put on each row and column?
Can you complete this jigsaw of the multiplication square?
Use the interactivity to find all the different right-angled
triangles you can make by just moving one corner of the starting
Can you cover the camel with these pieces?
Can you find all the different ways of lining up these Cuisenaire
Can you hang weights in the right place to make the equaliser
How many trains can you make which are the same length as Matt's, using rods that are identical?
What happens when you try and fit the triomino pieces into these
Can you work out how to balance this equaliser? You can put more
than one weight on a hook.
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?
In this activity, the computer chooses a times table and shifts it. Can you work out the table and the shift each time?
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?
Use the interactivities to fill in these Carroll diagrams. How do you know where to place the numbers?
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 from 1 to 15 on the circles so that no
consecutive numbers lie anywhere along a continuous straight line?
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?
Use the number weights to find different ways of balancing the equaliser.
Try out the lottery that is played in a far-away land. What is the
chance of winning?
Make one big triangle so the numbers that touch on the small triangles add to 10. You could use the interactivity to help you.
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.
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....?
Imagine a wheel with different markings painted on it at regular
intervals. Can you predict the colour of the 18th mark? The 100th
How many triangles can you make using sticks that are 3cm, 4cm and 5cm long?
How many different triangles can you make on a circular pegboard that has nine pegs?
Explore the different tunes you can make with these five gourds.
What are the similarities and differences between the two tunes you
Use your mouse to move the red and green parts of this disc. Can
you make images which show the turnings described?
An odd version of tic tac toe