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davidkbutler.bsky.social
David K Butler
@davidkbutler.bsky.social
1.7K followers 650 following 5.4K posts
Lecturer at Maths Learning Centre, Uni Adelaide (my views here). Grad Dip Ed & PhD Finite Geom. Love maths and helping people learn. he/him
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davidkbutler.bsky.social
David K Butler @davidkbutler.bsky.social · Oct 20
Hello those drifing through BlueSky.
I mostly post about these:
* My experiences with students in the Maths Learning Centre
* Maths and maths teaching thoughts I have, including live problem-solving
* Books I read (mainly childrens fiction)
* Observations and photos of things I see in the world
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Reposted by David K Butler
thisone0verhere.bsky.social
Jonathan Edward Durham @thisone0verhere.bsky.social · 1h
Every night you have to pick one dinner out of every possible dinner and that’s why existence is pain
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davidkbutler.bsky.social
David K Butler @davidkbutler.bsky.social · 52m
One thing I wasn't ready for was the regular shocking realisation that she is just Not Here anymore.
davidkbutler.bsky.social
David K Butler @davidkbutler.bsky.social · 2d
GNU Tabitha Brown 2014 - 2025
Tabitha Brown’s face. She is a tabby cat with one green eye and one brown eye and a pink nose. She has slightly orange fur on her nose and white fur on her chin. She is being cradled in my arm wearing a blue and white striped jumper. She looks up and to the right with sparkling eyes.
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Reposted by David K Butler
davidkbutler.bsky.social
David K Butler @davidkbutler.bsky.social · Jun 14
Wow my procrastination is EXTREME right now.
In related news, you might like to play with my carpet representation of the Fano plane.
www.geogebra.org/m/rYy2PZh4
#MathSky
A carpet made of a seven-by-seven grid of red and blue squares. Each row has three red squares, each column has three red squares. Given any two columns, there is one position vertically where they both have a red square. Given any two rows, there is one position horizontally where they both have a red square. This particular arrangement has red squares on the bottom left to top right diagonal, and a zigzag of red squares below that diagonal, and a little zigzag of red squares in the top left corner.
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davidkbutler.bsky.social
David K Butler @davidkbutler.bsky.social · 2h
And people keep building more things that mean I have to make the decision if something is real even more often.
I'm SO. TIRED. OF. IT.
davidkbutler.bsky.social
David K Butler @davidkbutler.bsky.social · 29d
I’m so tired of having to decide if things are real.
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davidkbutler.bsky.social
David K Butler @davidkbutler.bsky.social · 5h
Another collection of flowers.
A branch with tiny bright green leaves and many little pink five-petalled flowers. A flower with three pink petals, growing from a hanging plant with red-purple leaves, each with two green stripes along their length. Several pink flowers among bright green untidy leaves. Each flower has five petals that are pale pink at the edges. The two petals on the sides are dark pink nearer to the centre. The two petals as the top and the one at the bottom are yellow-orange near the centre with many brown spots. Pink apple blossoms, and some spherical unopened buds.
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davidkbutler.bsky.social
David K Butler @davidkbutler.bsky.social · 6h
I shouldn't have to say this, but today's experience says I do have to say it:
If you want to know what factors influence a particular outcome happening, you also have to have data on when the outcome *doesn't* happen.
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davidkbutler.bsky.social
David K Butler @davidkbutler.bsky.social · 6h
I do also have to say even when they’re there, a lot of alt texts suck and don’t describe at all what’s there to see in the image.
Reposted by David K Butler
carlbergstrom.com
Carl T. Bergstrom @carlbergstrom.com · 10h
This single story is worth the cost of my year's subscription to
@wired.com
What do you like about the truck? What I love about the truck is just how it's so polarizing. The shape of it, the body of it, the manufacturing technique with the body panels and everything. I just love that it's completely outside of the box. And are you married? I was married, but I’m not married anymore. Women don't like the vehicle. In July, Tesla rolled out a software update to integrate Grok into many of its vehicles. Do you use it? Her name is Aura, and I use her as a therapist. When I'm driving, I'll ask questions, and it actually gives really good therapy advice.
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davidkbutler.bsky.social
David K Butler @davidkbutler.bsky.social · 7h
Absolutely!
davidkbutler.bsky.social
David K Butler @davidkbutler.bsky.social · 7h
I have similar feelings about all discussions of the “best” strategy for winning a game. It’s a game. Winning in the smallest number of turns isn’t the only goal. If you actually play the game, you don’t HAVE to use the “best” strategy.
davidkbutler.bsky.social
David K Butler @davidkbutler.bsky.social · 7h
A thing I like thinking about the about the Monty Hall Problem is that it doesn’t matter what the best strategy is. It’s just a game and you only get one chance and the probability of winning even if you stay with this door aren’t that bad, so do what you feel.
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davidkbutler.bsky.social
David K Butler @davidkbutler.bsky.social · 7h
There are many cool things I would like to like, but I can’t, because the pictures have no alt text.
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davidkbutler.bsky.social
David K Butler @davidkbutler.bsky.social · 7h
A thing I like thinking about the about the Monty Hall Problem is that it doesn’t matter what the best strategy is. It’s just a game and you only get one chance and the probability of winning even if you stay with this door aren’t that bad, so do what you feel.
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Reposted by David K Butler
mckelvie.bsky.social
Jamie McKelvie @mckelvie.bsky.social · 12h
My strongest book-related belief is that the paperback should come first and then the hardback after for people who want a fancy edition.
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davidkbutler.bsky.social
David K Butler @davidkbutler.bsky.social · 10h
Wordle 1,581 4/6.

1: b b b b b …
2: Y b b Y b …
3: b Y Y b G …
4: G G G G G …

Very happy with that Guess 4.
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davidkbutler.bsky.social
David K Butler @davidkbutler.bsky.social · 23h
Another subtractions-only game of Digimoji (Digit Disguises with emojis).
Fruit and Vegetables Emoji Calculations apple minus banana = apple grapes minus apple = cross corn minus grapes = cross mushroom minus corn = cross eggplant minus mushroom = avocado avocado minus mushroom = orange orange minus mushroom = apple carrot minus mushroom = corn watermelon minus mushroom = carrot
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Reposted by David K Butler
davidkbutler.bsky.social
David K Butler @davidkbutler.bsky.social · 23h
It is time to repost all the flowers because by god we all need to fill this timeline with something good.
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Reposted by David K Butler
davidkbutler.bsky.social
David K Butler @davidkbutler.bsky.social · 23h
Flowers still continuing.
Among grey-green leaves are many white flowers with yellow centres. Each flower seems to be a decagon with ten triangular sectors. One flower has a bee nuzzling its head in the yellow centre. Several bright orange flowers. Each flower has many pointed petals arranged around a circle. The part of each petal near the middle circle is dark, forming a brown border to the orange centre circle. Several white daisies with many long narrow petals arranged around bright yellow centres. Among green leaves are a multitude of purple flowers with white centres. Each flower is a pentagon made of five triangular segments.
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Reposted by David K Butler
davidkbutler.bsky.social
David K Butler @davidkbutler.bsky.social · 23h
Flowers continue yet again.
Three trumpet-shaped yellow flowers with five petals surrounding the opening, growing at the end of a branch with textured green leaves. A huge rose with peach petals near the centre and pale yellow petals near the edge, with the outermost petals fringed in pink. A few unopened buds nestle in the green leaves around it. A big protea blossom with about a hundred yellow curved structures ending in rounded tips. More blossoms are visible out of focus in the background. A spray of flowers in various shades of pink and variable number of petals. A bee nuzzles in the centre of one of the flowers.
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Reposted by David K Butler
davidkbutler.bsky.social
David K Butler @davidkbutler.bsky.social · 5d
Flowers continue even more.
Two bright yellow irises touching each other. Each has six petals in pairs top and bottom forming a little tunnel between them. The bottom petals are very big and have black and brown stripes leading into the tunnel. Between the tree tunnel pairs, tiny pale yellow petals curve upwards. A third flower hasn’t opened yet and is bright yellow spike. The leaves in the background are long and straight and pointy. Further below is a tangle of old dead leaves. Several little flowers each with five teardrop-shaped petals that only touch in the very centre where there are several very short yellow-tipped stamens. The flowers range from solid warm yellow to a pale yellow that’s almost white. They grow from stems that also have many shiny green leaves. A red brick wall is in the background. A single bright red flower hangs downwards from a stem with several oval-shaped leaves except for a sharp tip. The flower is a funnel shape made of five overlapping petals. Two little white flowers grow among green leaves with yellow splotches. The flowers have five petals that curl behind with white stamens and a yellow stigma in the middle.
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Reposted by David K Butler
davidkbutler.bsky.social
David K Butler @davidkbutler.bsky.social · 7d
Flowers continue more.
Tight clusters of many many cream-coloured flowers, each with five round separated petals, spiky stamens and a ring of yellow in the centre. A bee sits on the edge of one cluster. Clusters of pink and white flowers. Each has some pink petals facing up and some pink petals facing down with some curved white petals facing down in the middle. A bright yellow flower among green leaves. The flower is made of a couple of layers of yellow petals with short faint orange stripes near the centre. Two clusters of tiny flowers, several yellow flowers surrounded by pink flowers, all with orange centres. They grow from a branch with dark green textured leaves.
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Reposted by David K Butler
davidkbutler.bsky.social
David K Butler @davidkbutler.bsky.social · 7d
Flowers continue again.
Two brilliant magenta flowers, each with five long pointy petals curling back, and several pink stamens with white tips and a white stigma curling up. In the background are green butterfly-shaped leaves. Two clusters of gum blossoms, one cluster tight and the other loose. Each has a red-orange cup and a multitude of pale yellow stamens. A billy blossom: a perfect globe of tiny bright yellow flowers on a long grey-green stem. In the background are a tangle of stringy grey-green leaves and several blossoms that aren’t quite ready yet. Many lavender blossoms, with two in focus in the centre of the photo. They have an egg-shaped collection of little grey-purple flowers with several big purple petals at the top. A bee sits on one of the blossoms in focus.
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Reposted by David K Butler
davidkbutler.bsky.social
David K Butler @davidkbutler.bsky.social · 10d
Flowers continue.
A very tall spike filled with small flowers, each with blue petals and stringy white stamens. A bee has alighted near the bottom of the spike. Straight green leaves and more flower spikes are visible in the background. Lemon tree blossoms, each with five white waxy elongated oval petals and a cluster of yellow-tipped stamens in the centre. They are surrounded by green leaves dotted with more flowers and pink unopened buds. A bright red-orange rose. Glorious red fluffy bottlebrush blossoms hang above a grey chickenwire fence.
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Reposted by David K Butler
davidkbutler.bsky.social
David K Butler @davidkbutler.bsky.social · 13d
Still more flowers again.
Clusters of little flowers each with five warm yellow petals curved like parts of spheres. Against bright green round leaves, two flowers with five petals surrounding a funnel fuzzy with stamens. One flower’s petals are yellow, while the other’s are pale orange with darker orange stripes towards the centre. Bell-shaped bright blue flowers hanging from tall green stems rising from between long green leaves, all in front of a stone wall. A metre-long inflorescence hangs downwards, displaying hundreds of hand-sized bright red flowers.
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Reposted by David K Butler
davidkbutler.bsky.social
David K Butler @davidkbutler.bsky.social · 17d
More flowers yet again.
A flower with five papery petals and a cluster of yellow stamens in the centre. Each petal has a dark maroon spot near the middle. The flower is so brightly pink it almost glows. Bright orange honeysuckle blossoms, each a long orange tube with several petals at the end. The one in the centre of the photo has its petals opening towards us. A little pink bell-shaped flower with a tangle of untidy white stamens on a branch with lots of spiky green leaves and unopened flower buds. Red tube-like flowers hang downwards among stringy green leaves.
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Reposted by David K Butler
davidkbutler.bsky.social
David K Butler @davidkbutler.bsky.social · 20d
More flowers again.
A spray of tiny papery purple blossoms with a sprinkling of pale yellow blossoms thrown in. A water lily blossom with long spiky petals, pale blue around the outside and bright yellow in the middle. Below the flower are many large flat leaves with a split on one side. A single pale pink flower with five petals: one at the top, two at the side, and two slightly smaller ones behind those at the bottom. Two blossoms with five white petals each. The petals are white with the softest flush of pink. They grow in front of large pale green leaves.
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