Thinking
is play.

For pupils, teachers, mentors and puzzle lovers. Since 1991 we have been promoting logic and logical thinking, mathematics and spatial reasoning — through the Logika & Recreational Mathematics magazine, books, competition materials and construction kits.

?Brain teaserKnight or knave? Click and check

Naslovnica: 34. letnik (2024/2025), tretja številka

Current issueSL

Logika & razvedrilna matematika
Volume 34 · No. 3 · 2024/2025

In this issue

The third issue of volume 34 is full of puzzles with numbers, colours and space: colour sudoku, sudoku with polygons and letters, Latin squares, Futoshiki, cross sums and cross products.

At its heart is a long run of mazes — on a cube, on polyhedra, on a map, on surfaces and on nets of a cylinder and a cone — followed by a logic problem, a problem in Esperanto, new problems and puzzles from the Logična pošast competition, with solutions at the end.

Read the PDF

Brain teaser

An island is home to knights, who always tell the truth, and knaves, who always lie. You meet Ana and Bor.

Ana says: “We are both knaves.”

Who is who?

Ana

Bor

Izidor Hafner

Founder of Logika and of the logic competitions

Former lecturer of mathematics and computer programming at the Faculty of Electrical Engineering, University of Ljubljana, founder of the competitions in logic and recreational mathematics, and editor of the magazine. Author of most of the problems and materials on this site and of many interactive Wolfram Demonstrations.

1991 Founds Logika and the Logika & Recreational Mathematics magazine
2000 Order of Freedom of the Republic of Slovenia
2009 National Education Award
2014 Honorary Member of DMFA Slovenia

Books, toys and the House of Polyhedra

Ten books we have published, the JOVO and Polydron construction kits we sell, Zometool, and the House of Polyhedra exhibition we run with the Mathema institute.

For teachers and mentors

Articles on the basics of logic, tests for the elective subject Logic, and materials for polyhedra workshops.

Thinkingis play.