We write this down today as a summation formula. This theorem, that the sum of subsequent odd integers starting with one is a square number, was already known in antiquity. Today we prove this with algebra, but algebra was not known to the Greeks.

	Arithmetic and Weaving in Antiquity A pebble proof of the incommensurability in the square

	We write this down today as a summation formula. This theorem, that the sum of subsequent odd integers starting with one is a square number, was already known in antiquity. Today we prove this with algebra, but algebra was not known to the Greeks.