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This is the title page of the 1640 printing of Galileo's Operation of the Geometrical and Military Compass, originally published privately in 1606. Galileo had invented a version of this geometrical compass a few years earlier and evidently gave copies of this manual to those who bought the compass. The compass had many uses, from performing square root calculations to determining ranges of cannons to solving surveying problems.
NCTM Annual Meeting in St. Louis
In this article which won the 2005 prize of HOMSIGMAA, the author discusses Eratosthenes' argument to determine the size of the earth as well as possibilities for the size which Eratosthenes found (in modern measures).
Given a semicircle, Prove that if O is the circle's center, DO=OE.
Two cog-wheels, one having 26 cogs, and the other 20 cogs, run together. In how many revolutions of the larger wheel will the smaller gain in 12 revolutions?
The radius of a circle is 3.20 meters. Compute to within .001m the areas of the inscribed and circumscribed equilateral triangles.
After a terrible battle it is found that 70% of the soldiers have lost an eye.

A detailed study of the cycles of the Mayan calendar, along with some other ancient calendars.

A man went to a draper and bought a length of cloth 35 braccia long to make a suit of clothes.
The cost per hour of running a certain steamboat is proportional to the cube of its velocity in still water. At what speed should it be run to make a trip up stream against a four-mile current most economically?