60Lower Secondary big button pagehttp://nrich.maths.org/secondary-loweren 2012 http://nrich.maths.org/public/terms.phpNumber Teasershttp://nrich.maths.org/12099Wed, 01 Dec 1999 00:00:01 +0000Unequal AveragesPlay around with sets of five numbers and see what you can discover about different types of average...http://nrich.maths.org/11281Mon, 01 Sep 2014 00:00:01 +0100MaxagonWhat's the greatest number of sides a polygon on a dotty grid could have?http://nrich.maths.org/11236Wed, 01 Jul 2015 00:00:01 +0100Completing QuadrilateralsWe started drawing some quadrilaterals - can you complete them?http://nrich.maths.org/11234Wed, 01 Apr 2015 00:00:01 +0100Puzzling Place ValueCan you explain what is going on in these puzzling number tricks?http://nrich.maths.org/11215Wed, 01 Apr 2015 00:00:01 +0100Growing SurprisesCan you find the connections between linear and quadratic patterns?http://nrich.maths.org/11212Fri, 01 May 2015 00:00:01 +0100Regular Hexagon LoopsMake some loops out of regular hexagons. What rules can you discover?http://nrich.maths.org/11206Wed, 01 Jul 2015 00:00:01 +0100Guess my QuadHow many questions do you need to identify my quadrilateral?http://nrich.maths.org/11202Wed, 01 Jul 2015 00:00:01 +0100Square Number SurprisesThere are unexpected discoveries to be made about square numbers...http://nrich.maths.org/11194Wed, 01 Apr 2015 00:00:01 +0100Garden ShedCan you minimise the amount of wood needed to build the roof of my garden shed?http://nrich.maths.org/11190Mon, 01 Sep 2014 00:00:01 +0100Multiple SurprisesSequences of multiples keep cropping up...http://nrich.maths.org/11173Wed, 01 Apr 2015 00:00:01 +0100Fibonacci SurprisesPlay around with the Fibonacci sequence and discover some surprising results!http://nrich.maths.org/11164Wed, 01 Apr 2015 00:00:01 +0100Perimeter ChallengeCan you deduce the perimeters of the shapes from the information given?http://nrich.maths.org/11119Mon, 01 Sep 2014 00:00:01 +0100ReversalsWhere should you start, if you want to finish back where you started?http://nrich.maths.org/11118Mon, 01 Sep 2014 00:00:01 +0100OverlapsCan you find ways to put numbers in the overlaps so the rings have equal totals?http://nrich.maths.org/11112Mon, 01 Sep 2014 00:00:01 +0100Forwards Add BackwardsWhat happens when you add a three digit number to its reverse?http://nrich.maths.org/11111Mon, 01 Sep 2014 00:00:01 +0100Add to 200By selecting digits for an addition grid, what targets can you make?http://nrich.maths.org/11110Mon, 01 Sep 2014 00:00:01 +0100ImpossibilitiesJust because a problem is impossible doesn't mean it's difficult...http://nrich.maths.org/11109Mon, 01 Sep 2014 00:00:01 +0100CryptarithmsCan you crack these cryptarithms?http://nrich.maths.org/11107Mon, 01 Sep 2014 00:00:01 +0100Quadrilaterals in a SquareWhat's special about the area of quadrilaterals drawn in a square?http://nrich.maths.org/11105Mon, 01 Sep 2014 00:00:01 +0100Triangles in a SquareWhat are the possible areas of triangles drawn in a square?http://nrich.maths.org/11017Mon, 01 Sep 2014 00:00:01 +0100Making a DifferenceHow many different differences can you make?http://nrich.maths.org/11012Wed, 01 Apr 2015 00:00:01 +0100Number ShacksCan you figure out how sequences of number shacks are generated?http://nrich.maths.org/11008Mon, 01 Sep 2014 00:00:01 +0100The Lives of PresidentsDo Presidents of the USA live longer now than in the past?http://nrich.maths.org/11007Mon, 01 Sep 2014 00:00:01 +0100WipeoutCan you do a little mathematical detective work to figure out which number has been wiped out?http://nrich.maths.org/10996Mon, 01 Sep 2014 00:00:01 +0100About AverageCan you find sets of numbers which satisfy each of our mean, median, mode and range conditions?http://nrich.maths.org/10995Mon, 01 Sep 2014 00:00:01 +0100Combining LengthsHow many different lengths is it possible to measure with a set of three rods?http://nrich.maths.org/10897Thu, 01 May 2014 00:00:01 +0100Climbing the StairsIn how many ways can I get upstairs?http://nrich.maths.org/10871Thu, 01 May 2014 00:00:01 +0100You Can't Make an Omelette...Can you devise the most efficient strategy for finding the highest floor from which you can drop an egg safely?http://nrich.maths.org/10870Tue, 01 Apr 2014 00:00:01 +0100Going to the CinemaA cinema has 100 seats. Is it possible to fill every seat and take exactly £100?http://nrich.maths.org/10868Thu, 01 May 2014 00:00:01 +0100