#100factorial
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davidkbutler.bsky.social
An unexpected use of the upscale pattern blocks at #100factorial yesterday @mathforlove.bsky.social
A tower made of green wooden triangles. Each layer is made of four triangles: three standing on their sides and one flat on the tops of the three points. Each layer uses smaller triangles than the layer below.
September 23, 2026 at 7:49 PM
davidkbutler.bsky.social
Pattern block and mirror play at #100factorial today.
December 13, 2023 at 3:36 AM
davidkbutler.bsky.social
A pattern block design and how it looks when you put the mirrors in two different places. #100factorial
February 14, 2024 at 12:41 AM
davidkbutler.bsky.social
Caught some very interesting shadows in the angled mirrors at #100factorial today.
January 17, 2024 at 2:59 AM
davidkbutler.bsky.social
One thing I love about #100factorial is the sheer excitement when there is more than one solution and the natural instinct to compare them.
davidkbutler.bsky.social David K Butler @davidkbutler.bsky.social · 9d
Another Quader Views puzzle at #100factorial this week.
A whiteboard has Quader Views written at the top. A little green 3D cube is drawn with T on the top, F on the front and S on the side. Under the title are three shapes made of individual squares labelled F, S, T. F has a row of three squares at the bottom, then a row of two squares and then one square. The rightmost edge of each row are aligned. T is a three by three square with the top left and bottom right squares removed. S has a two rows of three squares at the bottom, and another square in the middle at the top. Four shapes made of cubes on a table. They are different, but all have the same view from this angle. Each has the faces of the cubes decorated differently.
September 18, 2026 at 3:42 AM
davidkbutler.bsky.social
Playing Digit Disguises mod 10 at #100factorial today and it’s just awesome.

www.adelaide.edu.au/mathslearnin...
Digit Disguises
www.adelaide.edu.au
March 19, 2025 at 2:36 AM
davidkbutler.bsky.social
Pattern blocks in the angled mirrors by Laura at #100factorial today.
A design using pattern blocks between a pair of angled mirrors. The blocks and their reflections make a carpet of yellow hexagons, with red hexagons each made from two trapeziums and one green hexagon in the middle made from six triangles.
January 22, 2025 at 5:19 AM
davidkbutler.bsky.social
Particularly gorgeous design with the upscale pattern blocks at #100factorial today, especially considering it’s only two colours.
A design made of pattern blocks between two angled mirrors looks like a giant 3D flower. Three different sizes of yellow hexagons step upwards, with tan rhombuses making flower-like shapes in the corners and on the very top.
April 1, 2026 at 9:12 AM
davidkbutler.bsky.social
Today at #100factorial we got out the other polydron shapes other than triangles. And what do you do with all the triangles we usually play with? Obviously you stuff them inside a great big truncated icosahedron. Well, temporarily.
August 5, 2026 at 7:43 AM
davidkbutler.bsky.social
The students unprompted decided to explore ways to make hexagons out of the 21C pattern blocks at #100factorial yesterday.
Sixteen hexagons joined together, each made out of pattern blocks in different ways. Notable ones are * orange squares on their ends making a central stripe with four pink triangles finishing the sides * twenty four little triangles in two tones of green * a central green triangle surrounded by natural wood parallelograms, red trapeziums and pink triangles * a central yellow hexagon, three purple concave hexagons and three blue rhombuses
April 1, 2026 at 7:52 PM
davidkbutler.bsky.social
I got to play Home in One Piece at #100factorial today. Damn I love this game. drive.google.com/file/d/1njwv...
Home-in-One-Piece-2017-Making-Your-Own-Sense.pdf
drive.google.com
October 29, 2025 at 4:49 AM
davidkbutler.bsky.social
Two different games of Ceiling Jenga at #100factorial yesterday. (Rules are here: davidkbutler.xyz/2025/12/01/j...)
A tower of Jenga blocks with the blocks in all sorts of strange orientations. Of particular note are a couple of blocks standing upright one on top of the other, balancing on some blocks cantilevered out the side. A tower of Jenga blocks with the blocks in all sorts of strange orientations. Of particular note is the wide top layer with at least six blocks in multiple orientations. A hand is holding another block ready to put it on the tower.
September 23, 2026 at 7:55 PM
davidkbutler.bsky.social
#100Factorial today, with people doing various activities. We had numbers and letters, logic puzzles and several picture books with mathematical themes.
About ten people doing activities at several whiteboards outside on a concrete courtyard. A sandwich board in the foreground has a yellow sign saying One Hundred Factorial.
August 26, 2026 at 9:14 AM
davidkbutler.bsky.social
Two stages of a pattern blocks design between two mirrors, at #100factorial yesterday.
The designer was unsatisfied with her first design, wanting a bigger triangle to fill the corner next to the orange square. I suggested making a bigger pink triangle out of four smaller ones and off she went.
A pattern block design between two angled mirrors so that the design is reflected around making something like a snowflake. It uses blocks in many colours and shapes. The previous design has been extended to the mirrors and out beyond the mirrors so that the reflections make it very very large. Several areas parts are made of multiple of the same shape joined together.
September 23, 2026 at 11:55 PM
davidkbutler.bsky.social
A completed Numbers Game from #100factorial today. There were some pretty cool moves made today!
December 13, 2023 at 4:59 AM
davidkbutler.bsky.social
A seven-year-old kid came to #100factorial this week and played with Alex’s Snake puzzle toys. He made concentric square rings, but couldn’t finish the outermost ring. Then he figured out how to finish it.
A construction made from toys a bit like Rubik’s Snake. They have been made into concentric square rings. A square in the middle and then four rings around it. Another ring around the very outside is incomplete. The same picture as before, but the outermost square has been filled in by removing the second square from the inside.
December 19, 2024 at 8:30 AM
davidkbutler.bsky.social
Pattern block and mirror play at #100factorial today.
December 13, 2023 at 3:41 AM
davidkbutler.bsky.social
At #100factorial today, we asked what was the most room a Herzberger Quader structure could take up on the floor. This one has what we think is the bounding rectangle with both the biggest area and biggest perimeter.
A shape made of big cardboard cubes zigzags across the floor, the cubes touching along whole square faces, and taped together in various places. Three cubes pole upwards above the main layer at ground level. Overall, the zigzag is 18 cubes wide and 18 cubes long.
April 29, 2026 at 7:35 AM
davidkbutler.bsky.social
Five hours until the first #100factorial session of the year!
10am to 1pm Level 4 Hub Central Uni of Adelaide.
Everyone welcome to join in the mathsy play.
www.adelaide.edu.au/mathslearnin...
January 16, 2024 at 6:33 PM
davidkbutler.bsky.social
Can I just say how much joy #100factorial is giving me this year? It is such a pleasure to watch my regular students share mathematical play with each other and with the randoms who pop in just for today. The brightest spot in my week.
May 29, 2025 at 10:00 AM
davidkbutler.bsky.social
Suddenly realised that coming back to work means there's a #100factorial session this week! YAY!

Wed 22nd January 11am to 2pm (Adelaide time)
Level 4 Hub Central, Uni of Adelaide

Everyone welcome to join in the mathematical fun!
www.adelaide.edu.au/mathslearnin...
Mathematical Art & Play
www.adelaide.edu.au
January 20, 2025 at 8:09 AM
davidkbutler.bsky.social
A tessellation of spiralling pentagons and trapeziums, from #100factorial the other day.
A repeating pattern made of flat wooden blocks fitted together around gaps. The gaps are trapezium-shaped, alternating in orientation from one row to the next. The blocks are the concave pentagon shape you get when you remove a rhombus from a regular pentagon.
October 17, 2024 at 11:08 PM
davidkbutler.bsky.social
People were making dice out of the polydron triangles at #100factorial today and I decided to make a D12.
Each face is an inwards-pointing pyramid.
February 28, 2024 at 5:52 AM
davidkbutler.bsky.social
A wonderful design with the Golden Hexagons made by a student at #100factorial today.
A big yellow non-regular hexagon hexagons of the same but various smaller sizes and other colours lined up inside it.
February 12, 2025 at 8:45 AM
davidkbutler.bsky.social
Students completed the Tower challenge with the Herzberger Quader pieces at #100factorial today. Getting it down again was a bit scary!
September 2, 2026 at 5:51 AM