Prime numbers
game
Favourite
Dicey array
Watch the video of this game being played. Can you work out the rules? Which dice totals are good to get, and why?
problem
Favourite
Sieve of eratosthenes
Age
11 to 14
Challenge level
Follow this recipe for sieving numbers and see what interesting patterns emerge.
problem
Favourite
Fac-finding
Age
14 to 16
Challenge level
Lyndon chose this as one of his favourite problems. It is
accessible but needs some careful analysis of what is included and
what is not. A systematic approach is really helpful.
problem
Favourite
How much can we spend?
Age
11 to 14
Challenge level
A country has decided to have just two different coins, 3z and 5z
coins. Which totals can be made? Is there a largest total that
cannot be made? How do you know?
problem
Favourite
Number families
Age
11 to 14
Challenge level
How many different number families can you find?
problem
Favourite
Stars
Age
11 to 14
Challenge level
Can you work out what step size to take to ensure you visit all the dots on the circle?
problem
Favourite
Why 24?
Age
14 to 16
Challenge level
Take any prime number greater than 3 , square it and subtract one. Working on the building blocks will help you to explain what is special about your results.
problem
Favourite
One to eight
Age
11 to 14
Challenge level
Complete the following expressions so that each one gives a four
digit number as the product of two two digit numbers and uses the
digits 1 to 8 once and only once.
game
Favourite
Factors and multiples game
A game in which players take it in turns to choose a number. Can you block your opponent?