problem
Favourite
Marbles in a box
Age
11 to 16
Challenge level
How many winning lines can you make in a three-dimensional version of noughts and crosses?
problem
Favourite
Steel Cables
Age
14 to 16
Challenge level
Some students have been working out the number of strands needed for different sizes of cable. Can you make sense of their solutions?
problem
Favourite
How old am I?
Age
14 to 16
Challenge level
In 15 years' time my age will be the square of my age 15 years ago. Can you work out my age, and when I had other special birthdays?
problem
Favourite
Kite in a Square
Age
14 to 18
Challenge level
Can you make sense of the three methods to work out what fraction of the total area is shaded?