Hello, this is Mathmensch. Having been banned from two Wikipediae, I now mainly write wikibooks. You may contact me on any of my talk pages, but if you have a comment regarding a particular project, it probably makes sense to use the talk page on that very project.
You may visit a printing store and have them printed on an A4 sheet of sticky paper. (The keys will be the correct size, but you have to cut the sheet yourself.)
Latin, Cyrillic and DevanagariGreek, Hebrew and ArabicHangul, Hiragana and Farsi
Saw mill of Marcus Aurelius Ammianos
Construction of a parallelogram with ruler and compass
Some ordinal numbers
The decomposition of octane into butane and butene
The axial tilts (aka obliquity) of the earth and the moon
The so-called "Dandelin spheres" that prove that a closed conic section is an ellipse
Alhazen's geometrical proof of the formula for the sum of the first n numbers
