Use this grid to shade the numbers in the way described. Which
numbers do you have left? Do you know what they are called? Work
out Tom's number from the answers he gives his friend. He will
only answer 'yes' or 'no'. Use cubes to continue making the
numbers from 7 to 20. Are they sticks, rectangles or squares?
Can you make square numbers by adding two prime numbers
together? 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? 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? Using all ten cards from 0 to
9, rearrange them to make five prime numbers. Can you find any
other ways of doing it? These two group activities use
mathematical reasoning - one is numerical, one geometric. What
happens if you join every second point on this circle? How about
every third point? Try with