Dear Uncle Colin, I have two points and I want to construct a circle of a given radius that passes through them. Is it possible? — Every Underspecified Circle Lives Its Dream Hi, EUCLID, and thanks for your message! There are three possible answers to this, depending on the size
Read More →Some charitable suggestions Hello! I'm going to be a bit more personal than usual with this post; it's Boxing Day and in the spirit of goodwill to all, I wanted to highlight some of my favourite charities. As you know, the Flying Colours Maths blog is absolutely free of charge,
Read More →Dear Uncle Colin, I have a binomial expansion of $(1+x)^\frac{1}{2}$ and need to approximate $\sqrt{5}$. Apparently you need to substitute in $x=\frac{1}{4}$, but I’d have thought $x=4$ was a more obvious choice. What gives? — Roots Are Dangerous If Understood Sloppily Hi RADIUS, and thanks for your message! That does
Read More →Reports are filtering in to Flying Colours Towers about the mock exams recently taken by year 11s. Words like 'bloodbath' and 'disaster' feature prominently (my students, I should add, have acquitted themselves well and are in line to be mentioned in dispatches for bravery.) There's a reason the new-style papers
Read More →Dear Uncle Colin, How do you multiply big numbers like $2158 \times 1812$? I try to do it using the column method or the grid, but I always make mistakes. — A Desperately Desired Error Reduction Hi, ADDER, and thanks for your message! I’ve been playing with something midway between
Read More →As I happened to be in London last week, I took an afternoon to visit the Science Museum and, especially, the Winton Gallery exhibit on Mathematics. Maths! In the Science Museum! What a treat! Or so I hoped. The Winton Gallery: Mathematics There's a bit in Surely You're Joking, Mr
Read More →In this month's Christmassy episode of Wrong, But Useful, @reflectivemaths and I discuss: Number of the podcast: 9 Shout outs to: @aap03102 (Chris Smith) for his maths newsletter @mathistopheles (Thomas Oléron Evans) and @fryrsquared (Hannah Fry) for sending me a copy of their book @chalkdustmag for the lovely card @fryrsquared
Read More →(Based on something that actually happened!)
Read More →Dear Uncle Colin, My teacher suggested that if you factorise a quadratic and add the brackets, you get the derivative. I am now too frightened to sleep. — Quadratic Understanding Is Not Easy Hi, QUINE, and thanks for your message! To take a simple example, $x^2 + 5x + 6
Read More →My dear friend @ajk44 pointed me at a puzzle on the excellent Nrich site1, and I enjoyed it enough to share my solution. (If you don't want it spoiled, don't read beyond the blockquote.) Four jewellers had respectively 8 rubies, 10 sapphires, 100 pearls and 5 diamonds. Each gave one
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