Have You Got It?
Stage: 3 Challenge Level: 
Can you explain the strategy for winning this game with any target?
Latin Numbers
Stage: 4 Challenge Level:
Can you create a Latin Square from multiples of a six digit number?
Dozens
Stage: 2 and 3 Challenge Level:
Do you know a quick way to check if a number is a multiple of two? How about three, four or six?
Square It
Stage: 3 and 4 Challenge Level:
Players take it in turns to choose a dot on the grid. The winner is the first to have four dots that can be joined to form a square.
Warmsnug Double Glazing
Stage: 3 Challenge Level:
How have "Warmsnug" arrived at the prices shown on their windows? Which window has been given an incorrect price?
Product Sudoku
Stage: 3 Challenge Level:
The clues for this Sudoku are the product of the numbers in adjacent squares.
Factors and Multiples Game
Stage: 2, 3 and 4 Challenge Level:
A game in which players take it in turns to choose a number. Can you block your opponent?
Diamond Collector
Stage: 3 Challenge Level:
Collect as many diamonds as you can by drawing three straight lines.
Crossing the Bridge
Stage: 3 Challenge Level:
Four friends must cross a bridge. How can they all cross it in just 17 minutes?
Cops and Robbers
Stage: 2, 3 and 4 Challenge Level:
Can you find a reliable strategy for choosing coordinates that will locate the robber in the minimum number of guesses?
Dicey Operations
Stage: 3 Challenge Level:
Who said that adding, subtracting, multiplying and dividing couldn't be fun?
Wipeout
Stage: 3 Challenge Level:
Can you do a little mathematical detective work to figure out which number has been wiped out?
11x11 Square
Stage: 3 and 4 Challenge Level:
Here's a neat trick you can do with an 11 by 11 square...
River Crossing
Stage: 3 Challenge Level:
There is nothing half so much worth doing as simply messing about in boats...
Gabriel's Problem
Stage: 3 Challenge Level:
Gabriel multiplied together some numbers and then erased them. Can you figure out where each number was?
NRICH is part of the family of activities in the Millennium Mathematics Project.