- Irrationality Of E 17/10/2010 01:00
Prove that e is irrational.

Problem ID: 377 (17 Oct 2010) / Difficulty: 4 star - Rectangle Construction 17/10/2010 01:00
Find the connection between the constructed length and the original rectangle.

Problem ID: 376 (17 Oct 2010) / Difficulty: 2 star - Inscribed Circle In Isosceles Triangle 16/08/2010 01:00
Find the radius of the circle inscribed inside the isosceles triangle.

Problem ID: 375 (16 Aug 2010) / Difficulty: 2 star - Multiplying Magic Square 16/08/2010 01:00
Show how the values 1, 2, 4, 8, 16, 32, 64, 128, and 256 can be placed in a 3x3 square grid so that the product of each row, column, and diagonal gives the same value.

Problem ID: 374 (16 Aug 2010) / Difficulty: 3 star - Polynomial Roots 07/08/2010 01:00
Prove that the roots of the polynomial, x

Problem ID: 373 (07 Aug 2010) / Difficulty: 3 star^{n}+ c_{n-1}x^{n-1}+ ... + c_{2}x^{2}+ c_{1}x + c_{0}= 0, are irrational or integer. - Hops And Slides But Never Square 07/08/2010 01:00
Prove that the minimum number of moves to completely reverse the positions of the coloured counters can never be square.

Problem ID: 372 (07 Aug 2010) / Difficulty: 3 star - Irrationality Of Pi 24/12/2009
Prove that π is irrational.

Problem ID: 371 (24 Dec 2009) / Difficulty: 4 star - Square And Round Plugs 24/12/2009
Which fits better... a round plug in a square hole or a square plug in a round hole?

Problem ID: 370 (24 Dec 2009) / Difficulty: 2 star - Algebraic Cosine 30/11/2009
Prove that cos(x) is algebraic if x is a rational multiple of Pi.

Problem ID: 369 (30 Nov 2009) / Difficulty: 4 star - Inscribed Square 30/11/2009
Find the side length of the square inscribed inside the right angled triangle.

Problem ID: 368 (30 Nov 2009) / Difficulty: 2 star - Infinite Circles 15/11/2009
What fraction of the large red circle do the infinite set of smaller circles represent?

Problem ID: 367 (15 Nov 2009) / Difficulty: 4 star

- Approaching Midnight Start Time 01/02/2014 00:00Bernard played Approaching Midnight and wondered whether the start time affects who wins.
- Approaching Midnight Taking it Further 01/02/2014 00:00Here we offer some suggestions about how you could take the Approaching Midnight game further.
- Approaching Midnight First or Second? 01/02/2014 00:00Jennie tried the Approaching Midnight game and wondered if it matters whether you go first or second.
- Approaching Midnight Jump Straight In 01/02/2014 00:00If you'd like to explore the game freely, without any nudges from us, choose this version.
- Strange Bank Account (part 2) 01/05/2013 00:00Investigate different ways of making £5 at Charlie's bank.
- Solution 01/11/2013 00:00Solution to TWO and TWO
- Dotty Grids - Exploring Area 01/02/2014 00:00I wonder what we can find out about the areas of polygons drawn on dotty grids...
- What's the Weather Like? 01/10/2013 00:00With access to weather station data, what interesting questions can you investigate?
- Dotty Grids - Drawing Polygons 01/02/2014 00:00I wonder which polygons we can draw on dotty paper...
- Dotty Grids - Exploring Distance 01/02/2014 00:00I wonder what we can find out about distances along grid lines...
- Dotty Grids - Exploring Coordinates and Vectors 01/02/2014 00:00I wonder what we can find out when using coordinates and vectors on dotty grids...
- Advanced Mathematics on Dotty Grids 01/03/2014 00:00A dotty grid is a very simple mathematical structure that offers potential for very deep thought...
- Picture This! 01/11/2012 00:00
- Nine Eigen 01/02/2011 00:00Explore how matrices can fix vectors and vector directions.
- Sorted 01/10/2012 00:00How can you quickly sort a suit of cards in order from Ace to King?

- What’s the Deal with Euclid’s Fourth Postulate? 21/04/2014 13:30
- A Month of Math, Magic and Mystery 16/04/2014 16:52
- The Secret Spiritual History of Calculus 14/04/2014 13:00
- 5 Tips for Faster Mental Division (Part 2) 13/04/2014 15:00
- 5 Tips for Faster Mental Division (Part 1) 12/04/2014 15:00
- Measure Yourself by the Standard of the Capybara 11/04/2014 13:30
- The Slowest Way to Draw a Lute 07/04/2014 13:30
- How to Calculate with Significant Figures 05/04/2014 15:00
- A Brief History of Infinitesimals: The Idea That Gave Birth to Modern Calculus 04/04/2014 14:00
- Magic, Puzzles Delight Math Fans at G4G 01/04/2014 22:15
- Graham’s Number Is Too Big for Me to Tell You How Big It Is 01/04/2014 13:15
- Unscientific Unamerican, and Other April Fools' Jokes in SA History 01/04/2014 12:30
- Chaos Theory Pioneer Nabs Abel Prize 27/03/2014 14:20
- Quantiphobia and the turning of morals into facts 25/03/2014 22:38
- When It Comes to the Baseball Stat Rage, Quantification Doesn't Always Make It Science 25/03/2014 12:45
- Mathematical Impressions: The Bicycle Pulling Puzzle 22/03/2014 12:00
- These Tips Can Drive You up the Wall 19/03/2014 11:45
- Take Me Out to the Run Expectancy Matrix Analysis 18/03/2014 15:00
- A Different Pi for Pi Day 14/03/2014 11:30
- Mathematical Patterns in Sea Ice Reveal Melt Dynamics 13/03/2014 18:55
- The Math Wars, Lewis Carroll Style 04/03/2014 13:30
- Equations Are Art inside a Mathematician’s Brain 04/03/2014 13:00
- A Fluid New Path in Grand Math Challenge 27/02/2014 20:00
- The Stunning Symbiosis between Math and Knitting [Slide Show] 24/02/2014 21:30
- The Stunning Symbiosis between Math and Knitting [Slide Show] 24/02/2014 21:00