Follow this recipe for sieving numbers and see what interesting patterns emerge.
Take the number 6 469 693 230 and divide it by the first ten prime
numbers and you'll find the most beautiful, most magic of all
numbers. What is it?
Work out Tom's number from the answers he gives his friend. He will
only answer 'yes' or 'no'.
What happens if you join every second point on this circle? How
about every third point? Try with different steps and see if you
can predict what will happen.
All strange numbers are prime. Every one digit prime number is
strange and a number of two or more digits is strange if and only
if so are the two numbers obtained from it by omitting either. . . .
Can you find a relationship between the number of dots on the
circle and the number of steps that will ensure that all points are
Can you make square numbers by adding two prime numbers together?
Factors and Multiples game for an adult and child. How can you make sure you win this game?
Arrange the four number cards on the grid, according to the rules,
to make a diagonal, vertical or horizontal line.
Using all ten cards from 0 to 9, rearrange them to make five prime
numbers. Can you find any other ways of doing it?
Using your knowledge of the properties of numbers, can you fill all the squares on the board?
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?
A man has 5 coins in his pocket. Given the clues, can you work out
what the coins are?
These two group activities use mathematical reasoning - one is
numerical, one geometric.
A game in which players take it in turns to choose a number. Can you block your opponent?
Use the interactivities to complete these Venn diagrams.