David Butler (@DavidKButlerUoA) of the Maths Learning Centre at the University of Adelaide runs a puzzle and games club called “One Hundred Factorial” (named after the first puzzle the club tackled – read more here).
Across the years, many of these puzzles have been shared through photos on Twitter using #100factorial. Here I aim to curate a list of all the puzzles that have been shared, with descriptions and possible solutions, eventually with some degree of organisation, to aid in finding puzzles quickly in the future.
Using any or all of the operations of addition, subtraction, multiplication, division and exponentiation (and brackets), and as many ofRead more.
One Spot Dice
You have two blank 6-sided dice. You are allowed to choose any number of the twelve faces and draw exactlyRead more.
Number of Letters
The numbers seven, eleven, fifteen, nineteen make a sequence where the numbers go up by 4 each time. But ifRead more.
Three boxes filled with lots of balls are on the table. One box is full of red balls, one isRead more.
Eight cubes are marked with one dot on two opposite faces, two dots on two opposite faces and three dotsRead more.
Convexity of Deltahedra
Claim: There is a convex deltahedron with every even number of faces from 4 to 20, except one. Investigating non-convexRead more.
A standard six-sided die spontaneously starts to divide like a living cell. The spots on the die move during theRead more.
Imagine your calculator is broken. Although it will still display numbers, only the 4 key, + key, = key, andRead more.
Four Dots, Two Distances
Find all configurations of four (distinct) points in the place that will determine exactly two distinct (non-zero) distances.Read more.
A positive integer is said to be jiggly if it has four digits, all non-zero, and no matter how youRead more.