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past issues

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Welcome to NRICH.

Puzzles

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Of course, if you want puzzles, there are hundreds of archived problems.

• 2 The ship's ladder problem
• 2 Subtraction puzzle
• 2 River crossing puzzles
  
  
• 3 Sum of numbers made from 1,2,3,4,5
• 3 Pizza Problem
• 3 Pentominos
• 3 What is the cube root of INVENTORY?
• 3 Alphanumerics (ABCD×4=DCBA)
• 3 STAR + EAST = LIGHT
• 3 Ball bearings
• 3 Travel on a river problem
• 3 Workers of different speeds
• 3 Bottles in milkcrate problem
• 3 Life or death
• 3 Crossing the desert puzzle
• 3 Puzzle collection
• 3 Great Granddad problem
• 3 Fly flying between two cars
• 3 Some Good Puzzles
• 3 The problem "rollerball"
• 3 5+5+5 = 550
• 3 Towers of Hanoi
• 3 Euler Problem
• 3 Money conundrum
• 3 Weighing puzzle
• 3 Toast puzzle
• 3 Open box net problem
• 3 How many men to pump the ship dry?
• 3 School sprinkler problem: is it on or off?
• 3 Motivate project: Mathematical surprises
• 3 Article: The Eternity Puzzle
  
  
• 4 Fair shares problem
• 4 Balance scale - how many weights do you need?
• 4 How many ways to make a cube from small cubes?
• 4 Missing numbers on two spun discs
• 4 Averages puzzle
• 4 Circumference problem
• 4 Hens and rabbits problem
• 4 Hens and rabbits problem; simultaneous equations (or not)
• 4 Speed/distance/time problem
• 4 Tiling a grid with tetrominos
• 4 Tournament problem
  
  
• 5 Logs puzzle
• 5 Window cleaning problem
• 5 Two Snakes eating each other