Use the interactivities to fill in these Carroll diagrams. How do you know where to place the numbers?
If you have only four weights, where could you place them in order
to balance this equaliser?
How have the numbers been placed in this Carroll diagram? Which
labels would you put on each row and column?
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?
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.
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?
Can you use the numbers on the dice to reach your end of the number line before your partner beats you?
An environment which simulates working with Cuisenaire rods.
Place the numbers 1 to 10 in the circles so that each number is the
difference between the two numbers just below it.
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?
Here is a chance to play a version of the classic Countdown Game.
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 complete this jigsaw of the multiplication square?
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?
Use the information about Sally and her brother to find out how many children there are in the Brown family.
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....?
An odd version of tic tac toe
Can you see why 2 by 2 could be 5? Can you predict what 2 by 10
Choose a symbol to put into the number sentence.
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 hang weights in the right place to make the equaliser
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?
Use the number weights to find different ways of balancing the equaliser.
Use the interactivity to sort these numbers into sets. Can you give
each set a name?
Place six toy ladybirds into the box so that there are two ladybirds in every column and every row.
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?
Can you put the numbers from 1 to 15 on the circles so that no
consecutive numbers lie anywhere along a continuous straight line?
Match the halves.
Use the interactivity to find all the different right-angled
triangles you can make by just moving one corner of the starting
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?
Investigate which numbers make these lights come on. What is the smallest number you can find that lights up all the lights?
Ben and his mum are planting garlic. Use the interactivity to help
you find out how many cloves of garlic they might have had.
Use the interactivity to find out how many quarter turns the man
must rotate through to look like each of the pictures.
Can you work out how to balance this equaliser? You can put more
than one weight on a hook.
Can you find just the right bubbles to hold your number?
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.
Incey Wincey Spider game for an adult and child. Will Incey get to the top of the drainpipe?
Move just three of the circles so that the triangle faces in the
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?
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?
Imagine a wheel with different markings painted on it at regular
intervals. Can you predict the colour of the 18th mark? The 100th
Try to stop your opponent from being able to split the piles of counters into unequal numbers. Can you find a strategy?
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?
Can you cover the camel with these pieces?