60Secondary Teacher Big Button Pagehttp://nrich.maths.org/teacher-secondaryen 2012 http://nrich.maths.org/public/terms.phpCodes, Inverses, and Thinking Mathematicallyhttp://nrich.maths.org/13356Wed, 01 Dec 1999 00:00:01 +0000Statement SnapYou'll need to know your number properties to win a game of Statement Snap...http://nrich.maths.org/13349Wed, 01 Dec 1999 00:00:01 +0000CodebreakersThis article for Primary and Secondary teachers is all about the mathematics behind solving puzzles, unravelling mysteries and breaking codes.http://nrich.maths.org/13332Wed, 01 Dec 1999 00:00:01 +0000Satisfying StatementsCan you find any two-digit numbers that satisfy all of these statements?http://nrich.maths.org/13325Wed, 01 Dec 1999 00:00:01 +0000The Simple LifeThe answer is $5x+8y$... What was the question?http://nrich.maths.org/13207Wed, 01 Dec 1999 00:00:01 +0000Mathematical EtudesThis article by Colin Foster presents the idea of mathematical etudes as a way to develop fluency without tedium.http://nrich.maths.org/13206Wed, 01 Dec 1999 00:00:01 +0000Almost OneChoose some fractions and add them together. Can you get close to 1?http://nrich.maths.org/13205Wed, 01 Dec 1999 00:00:01 +0000Alison's QuiltNine squares are fitted together to form a rectangle. Can you find its dimensions?http://nrich.maths.org/13124Tue, 01 Feb 2011 00:00:01 +0000Number FamiliesHow many different number families can you find?http://nrich.maths.org/13123Tue, 01 Feb 2011 00:00:01 +0000Shape ProductsThese eleven shapes each stand for a different number. Can you use the multiplication sums to work out what they are?http://nrich.maths.org/13079Tue, 01 Feb 2011 00:00:01 +0000More Isometric AreasIsometric Areas explored areas of parallelograms in triangular units. Here we explore areas of triangles...http://nrich.maths.org/11854Wed, 01 Dec 1999 00:00:01 +0000Isometric AreasWe usually use squares to measure area, but what if we use triangles instead?http://nrich.maths.org/11853Wed, 01 Dec 1999 00:00:01 +0000Towering TrapeziumsCan you find the areas of the trapezia in this sequence?http://nrich.maths.org/11449Sun, 01 Mar 2015 00:00:01 +0000Hollow SquaresWhich armies can be arranged in hollow square fighting formations?http://nrich.maths.org/11257Mon, 01 Sep 2014 00:00:01 +0100NRICH Resources for Every OccasionThis article highlights NRICH tasks that can be used for a variety of purposes in the classroom.http://nrich.maths.org/11252Mon, 01 Sep 2014 00:00:01 +0100What Are Rich Tasks?What are rich tasks and why do they matter?http://nrich.maths.org/11249Mon, 01 Sep 2014 00:00:01 +0100Tilted Squares - Teaching Using Rich TasksWatch Charlie and Alison teaching a lesson and read about the teaching points they consider to be important.http://nrich.maths.org/11248Mon, 01 Sep 2014 00:00:01 +0100Teaching Secondary Mathematics Using NRICH ResourcesAn introduction to using secondary NRICH activities in the classroom.http://nrich.maths.org/11121Wed, 01 Oct 2014 00:00:01 +0100Difference of Two SquaresWhat is special about the difference between squares of numbers adjacent to multiples of three?http://nrich.maths.org/11120Mon, 01 Sep 2014 00:00:01 +0100Pythagoras PerimetersIf you know the perimeter of a right angled triangle, what can you say about the area?http://nrich.maths.org/11106Mon, 01 Sep 2014 00:00:01 +0100Quadratic PatternsSurprising numerical patterns can be explained using algebra and diagrams...http://nrich.maths.org/11011Mon, 01 Sep 2014 00:00:01 +0100Mega Quadratic EquationsWhat do you get when you raise a quadratic to the power of a quadratic?http://nrich.maths.org/11009Wed, 01 Dec 1999 00:00:01 +0000What we think and why we think itThe Secondary Team's beliefs about teaching mathematics, and the ideas that have inspired us.http://nrich.maths.org/8068Thu, 01 Jan 2015 00:00:01 +0000Graphs of Changing AreasUse graphs to gain insights into an area and perimeter problem, or use your knowledge of area and perimeter to gain insights into the graphs...http://nrich.maths.org/7559Fri, 01 Jul 2011 00:00:01 +0100Charlie's Delightful MachineHere is a machine with four coloured lights. Can you develop a strategy to work out the rules controlling each light?http://nrich.maths.org/7024Tue, 01 Feb 2011 00:00:01 +0000A Little Light ThinkingHere is a machine with four coloured lights. Can you make two lights switch on at once? Three lights? All four lights?http://nrich.maths.org/7016Tue, 01 Feb 2011 00:00:01 +0000Cyclic QuadrilateralsDraw some quadrilaterals on a 9-point circle and work out the angles. Is there a theorem?http://nrich.maths.org/6624Tue, 01 Feb 2011 00:00:01 +0000Multiples SudokuEach clue in this Sudoku is the product of the two numbers in adjacent cells.http://nrich.maths.org/6434Tue, 01 Feb 2011 00:00:01 +0000Which Spinners?Can you work out which spinners were used to generate the frequency charts?http://nrich.maths.org/6123Mon, 01 Aug 2011 00:00:01 +0100Data MatchingUse your skill and judgement to match the sets of random data.http://nrich.maths.org/5933Tue, 01 Feb 2011 00:00:01 +0000Triangles in CirclesCan you find triangles on a 9-point circle? Can you work out their angles?http://nrich.maths.org/2844Tue, 01 Feb 2011 00:00:01 +0000Area LBy sketching a graph of a continuous increasing function, can you prove a useful result about integrals?http://nrich.maths.org/2375Tue, 01 Feb 2011 00:00:01 +0000Of All the AreasCan you find a general rule for finding the areas of equilateral triangles drawn on an isometric grid?http://nrich.maths.org/693Tue, 01 Feb 2011 00:00:01 +0000System SpeakFive equations... five unknowns... can you solve the system?http://nrich.maths.org/543Tue, 01 Feb 2011 00:00:01 +0000