Working systematically

  • Latin Squares
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    Latin Squares

    A Latin square of order n is an array of n symbols in which each symbol occurs exactly once in each row and exactly once in each column.
  • Maths Trails
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    Maths Trails

    The NRICH team are always looking for new ways to engage teachers and pupils in problem solving. Here we explain the thinking behind maths trails.
  • Integrated sums sudoku
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    Integrated Sums Sudoku

    The puzzle can be solved with the help of small clue-numbers which are either placed on the border lines between selected pairs of neighbouring squares of the grid or placed after slash marks on the intersections between two diagonally adjacent squares.

  • Placeholder: several colourful numbers
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    Binomial Coefficients

    An introduction to the binomial coefficient, and exploration of some of the formulae it satisfies.

  • Peg and Pin Boards
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    Peg and Pin Boards

    This article for teachers suggests activities based on pegboards, from pattern generation to finding all possible triangles, for example.