2021 Top Ten of Polemic for Mathematics

50,000

50,000 is the natural number that comes after 49,999 and before 50,001

Minimal prime (recreational mathematics)

In recreational number theory, a minimal prime is a prime number for which there is no shorter subsequence of its digits in a given base that form a prime. In base 10 there are exactly 26 minimal primes:2, 3, 5, 7, 11, 19, 41, 61, 89, 409, 449, 499, 881, 991, 6469, 6949, 9001, 9049, 9649, 9949, 60649, 666649, 946669, 60000049, 66000049, 66600049

Magic cube classes

Every magic cube may be assigned to one of six magic cube classes, based on the cube characteristics

Vish (game)

In the game of Vish, players compete to find circularity in dictionary definitions. Irish mathematician and physicist, John Lighton Synge, invented the multi-player, refereed game to emphasize the circular reasoning implicit in the defining process of any standard dictionary

Wythoff's game

Wythoff's game is a two-player mathematical subtraction game, played with two piles of counters. Players take turns removing counters from one or both piles; when removing counters from both piles, the numbers of counters removed from each pile must be equal. The game ends when one player removes the last counter or counters, thus winning

30 (number)

30 (thirty) is the natural number following 29 and preceding 31

Rectified truncated icosahedron

The rectified truncated icosahedron is a polyhedron, constructed as a rectified truncated icosahedron. It has 92 faces: 60 isosceles triangles, 12 regular pentagons, and 20 regular hexagons. It is constructed as a rectified truncated icosahedron, rectification truncating vertices down to mid-edges

Diagonal magic cube

The class of diagonal magic cubes is the second of the six magic cube classes, coming after the simple magic cubes

Original proof of Gödel's completeness theorem

The proof of Gödel's completeness theorem given by Kurt Gödel in his doctoral dissertation of 1929 is not easy to read today; it uses concepts and formalisms that are no longer used and terminology that is often obscure. The version given below attempts to represent all the steps in the proof and all the important ideas faithfully, while restating the proof in the modern language of mathematical logic. This outline should not be considered a rigorous proof of the theorem

Cuboid

In geometry, a cuboid is a hexahedron, a six-faced solid. Its faces are quadrilaterals. "Cuboid" means "like a cube", in the sense that by adjusting the length of the edges or the angles between edges and faces a cuboid can be transformed into a cube. In math language a cuboid is convex polyhedron, whose polyhedral graph is the same as that of a cube