Which achievements show egyptians' mathematical abilities

Okay, to get started, we are talking about c.3000 to c.300 BC. On tombs was some math written in ivory, or so, and these ivory labels had been used for "Tags" for grave goods. The evidence that Egyptians used mathematics happened during ca 2690–2180 BC is little, but can be seen on ivory inscriptions on walls. The earliest "correct" mathematics happened during the 12th dynasty, or ca 1990–1800 BC. It sometimes happened on material called "Kahun Papyri ".  The lines of a diagram are of a distance of one cubit, compared to a "unit Of Measurement". I hope I could help! :)