Hidden Treasures
To celebrate NRICH's 20th birthday, we've taken a look back in the archives and dusted off some problems from the early days, freshened them up, and added some new ideas. We hope you enjoy working on these hidden treasures!
Calendar Capers Age 11 to 14
Challenge Level
Challenge Level
Choose any three by three square of dates on a calendar page...
Counting Factors Age 11 to 14
Challenge Level
Challenge Level
Is there an efficient way to work out how many factors a large number has?
Latin Numbers Age 14 to 16
Challenge Level
Challenge Level
Can you create a Latin Square from multiples of a six digit number?
Building Tetrahedra Age 14 to 16
Challenge Level
Challenge Level
Can you make a tetrahedron whose faces all have the same perimeter?
Gift of Gems Age 14 to 16
Challenge Level
Challenge Level
Four jewellers share their stock. Can you work out the relative values of their gems?
Rationals Between... Age 14 to 16
Challenge Level
Challenge Level
What fractions can you find between the square roots of 65 and 67?
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NRICH is part of the family of activities in the Millennium Mathematics Project.
NRICH is part of the family of activities in the Millennium Mathematics Project.