Do you know a quick way to check if a number is a multiple of two? How about three, four or six?

A game for two people, or play online. Given a target number, say 23, and a range of numbers to choose from, say 1-4, players take it in turns to add to the running total to hit their target.

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.

How have "Warmsnug" arrived at the prices shown on their windows? Which window has been given an incorrect price?

The clues for this Sudoku are the product of the numbers in adjacent squares.

A game in which players take it in turns to choose a number. Can you block your opponent?

Collect as many diamonds as you can by drawing three straight lines.

Four friends must cross a bridge. How can they all cross it in just 17 minutes?

Can you find a reliable strategy for choosing coordinates that will locate the robber in the minimum number of guesses?

Who said that adding, subtracting, multiplying and dividing couldn't be fun?

Here's a neat trick you can do with an 11 by 11 square...

There is nothing half so much worth doing as simply messing about in boats...

Gabriel multiplied together some numbers and then erased them. Can you figure out where each number was?

A collection of short Stage 3 and 4 problems on Thinking Strategically.