There is a clock-face where the numbers have become all mixed up. Can you find out where all the numbers have got to from these ten statements?
Imagine a pyramid which is built in square layers of small cubes.
If we number the cubes from the top, starting with 1, can you
picture which cubes are directly below this first cube?
Ahmed is making rods using different numbers of cubes. Which rod is
twice the length of his first rod?
Cherri, Saxon, Mel and Paul are friends. They are all different
ages. Can you find out the age of each friend using the
Can you design a new shape for the twenty-eight squares and arrange
the numbers in a logical way? What patterns do you notice?
This magic square has operations written in it, to make it into a
maze. Start wherever you like, go through every cell and go out a
total of 15!
There are 44 people coming to a dinner party. There are 15 square
tables that seat 4 people. Find a way to seat the 44 people using
all 15 tables, with no empty places.
Can you each work out the number on your card? What do you notice?
How could you sort the cards?
Use the information about Sally and her brother to find out how many children there are in the Brown family.
Using the statements, can you work out how many of each type of
rabbit there are in these pens?
Zumf makes spectacles for the residents of the planet Zargon, who
have either 3 eyes or 4 eyes. How many lenses will Zumf need to
make all the different orders for 9 families?
Can you arrange 5 different digits (from 0 - 9) in the cross in the
In a Magic Square all the rows, columns and diagonals add to the 'Magic Constant'. How would you change the magic constant of this square?
This problem is based on the story of the Pied Piper of Hamelin. Investigate the different numbers of people and rats there could have been if you know how many legs there are altogether!
Katie had a pack of 20 cards numbered from 1 to 20. She arranged
the cards into 6 unequal piles where each pile added to the same
total. What was the total and how could this be done?
Use your logical-thinking skills to deduce how much Dan's crisps
and ice-cream cost altogether.
If the answer's 2010, what could the question be?
Try adding together the dates of all the days in one week. Now
multiply the first date by 7 and add 21. Can you explain what
Can you see how these factor-multiple chains work? Find the chain
which contains the smallest possible numbers. How about the largest
48 is called an abundant number because it is less than the sum of
its factors (without itself). Can you find some more abundant
What is the lowest number which always leaves a remainder of 1 when
divided by each of the numbers from 2 to 10?
What do you notice about the date 03.06.09? Or 08.01.09? This
challenge invites you to investigate some interesting dates
Can you fill in this table square? The numbers 2 -12 were used to
generate it with just one number used twice.
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?
This big box multiplies anything that goes inside it by the same number. If you know the numbers that come out, what multiplication might be going on in the box?
Work out Tom's number from the answers he gives his friend. He will
only answer 'yes' or 'no'.
Find the product of the numbers on the routes from A to B. Which
route has the smallest product? Which the largest?
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 see why 2 by 2 could be 5? Can you predict what 2 by 10
How would you count the number of fingers in these pictures?
Choose a symbol to put into the number sentence.
Bernard Bagnall recommends some primary school problems which use
numbers from the environment around us, from clocks to house
Look at what happens when you take a number, square it and subtract your answer. What kind of number do you get? Can you prove it?
These eleven shapes each stand for a different number. Can you use
the multiplication sums to work out what they are?
Which is quicker, counting up to 30 in ones or counting up to 300 in tens? Why?
A group of children are using measuring cylinders but they lose the
labels. Can you help relabel them?
There were chews for 2p, mini eggs for 3p, Chocko bars for 5p and
lollypops for 7p in the sweet shop. What could each of the children
buy with their money?
Explore Alex's number plumber. What questions would you like to ask? What do you think is happening to the numbers?
Suppose we allow ourselves to use three numbers less than 10 and
multiply them together. How many different products can you find?
How do you know you've got them all?
Well now, what would happen if we lost all the nines in our number
system? Have a go at writing the numbers out in this way and have a
look at the multiplications table.
Skippy and Anna are locked in a room in a large castle. The key to that room, and all the other rooms, is a number. The numbers are locked away in a problem. Can you help them to get out?
We can arrange dots in a similar way to the 5 on a dice and they
usually sit quite well into a rectangular shape. How many
altogether in this 3 by 5? What happens for other sizes?
Can you put the numbers 1 to 8 into the circles so that the four
calculations are correct?
Can you find which shapes you need to put into the grid to make the
totals at the end of each row and the bottom of each column?
What happens when you add the digits of a number then multiply the
result by 2 and you keep doing this? You could try for different
numbers and different rules.
56 406 is the product of two consecutive numbers. What are these
Tom and Ben visited Numberland. Use the maps to work out the number
of points each of their routes scores.
Can you work out what a ziffle is on the planet Zargon?
If you had any number of ordinary dice, what are the possible ways
of making their totals 6? What would the product of the dice be
Here is a picnic that Chris and Michael are going to share equally.
Can you tell us what each of them will have?