60Lower Secondary big button pagehttp://nrich.maths.org/secondary-loweren 2012 http://nrich.maths.org/public/terms.phpProbability and Evidencehttp://nrich.maths.org/12244Wed, 01 Dec 1999 00:00:01 +0000Introductory VideoAn introductory video to the Probability and Evidence collectionhttp://nrich.maths.org/12241Wed, 01 Dec 1999 00:00:01 +0000Matching CriminalsDNA profiling is an invaluable tool for the police. However, when it comes to probability, things aren't always as straightforward as they seem.http://nrich.maths.org/12215Wed, 01 Dec 1999 00:00:01 +0000The ELISA TestIn 1% of cases, an HIV test gives a positive result for someone who is HIV negative. How likely is it that someone who tests positive has HIV?http://nrich.maths.org/12178Wed, 01 Dec 1999 00:00:01 +0000Do Rare Events Happen?I'd be very surprised if I had three children all with the same birthday, but I read in the paper that it happened to one family...http://nrich.maths.org/12177Wed, 01 Dec 1999 00:00:01 +0000Trusting the TabloidsCan you match the cards and figure out whether the tabloid headlines can be trusted?http://nrich.maths.org/12172Wed, 01 Dec 1999 00:00:01 +0000Spots and Measles99% of people who have measles have spots. Ben has spots. Do you think he has measles?http://nrich.maths.org/12171Wed, 01 Dec 1999 00:00:01 +0000Risk and CrimeAre you at risk of being a victim of crime? How does your perception of that risk compare with the facts and figures?http://nrich.maths.org/12167Wed, 01 Dec 1999 00:00:01 +0000Statins and Risk"Statins cut the risks of heart attacks and strokes by 40%"<br />
Should the Professor take statins? Can you help him decide?http://nrich.maths.org/12165Wed, 01 Dec 1999 00:00:01 +0000Journey to SchoolHow risky is your journey to school?http://nrich.maths.org/12164Wed, 01 Dec 1999 00:00:01 +0000How Risky is a Bacon Sandwich?Newspapers said that eating a bacon sandwich every day raises the risk of bowel cancer by 20%. Should you be concerned?http://nrich.maths.org/12163Wed, 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 +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 +0100