Working systematically

  • Pole Star Sudoku 2
    problem

    Pole Star Sudoku 2

    Age
    11 to 16
    Challenge level

    This Sudoku, based on differences. Using the one clue number can you find the solution?

  • Quadruple Sudoku
    problem

    Quadruple Sudoku

    Age
    11 to 16
    Challenge level

    Four small numbers give the clue to the contents of the four surrounding cells.

  • Star Product Sudoku
    problem

    Star Product Sudoku

    Age
    11 to 16
    Challenge level

    The puzzle can be solved by finding the values of the unknown digits (all indicated by asterisks) in the squares of the $9\times9$ grid.

  • Bochap Sudoku
    problem

    Bochap Sudoku

    Age
    11 to 16
    Challenge level

    This Sudoku combines all four arithmetic operations.

  • Twin corresponding Sudoku III
    problem

    Twin Corresponding Sudoku III

    Age
    11 to 16
    Challenge level

    Two sudokus in one. Challenge yourself to make the necessary connections.

  • Rectangle Outline Sudoku
    problem

    Rectangle Outline Sudoku

    Age
    11 to 16
    Challenge level

    Each of the main diagonals of this sudoku must contain the numbers 1 to 9 and each rectangle width the numbers 1 to 4.

  • Olympic Logic
    problem

    Olympic Logic

    Age
    11 to 16
    Challenge level

    Can you use your powers of logic and deduction to work out the missing information in these sporty situations?

  • Small tomato seedlings in yellow pots.
    problem

    Middle Digit Mean

    Age
    11 to 16
    Challenge level

    Weekly Problem 16 - 2016
    How many three digit numbers have the property that the middle digit is the mean of the other two digits?

  • Twin Corresponding Sudoku
    problem

    Twin Corresponding Sudoku

    Age
    11 to 18
    Challenge level

    This sudoku requires you to have "double vision" - two Sudoku's for the price of one

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