[89]
Worker graffiti found at Giza suggest haulers were divided into zau (singular za), groups of 40 men, consisting of four sub-units that each had an "Overseer of Ten".[90][3]
As to the question of how over two million blocks could have been cut within Khufu's lifetime, stonemason Franck Burgos conducted an archaeological experiment based on an abandoned quarry of Khufu discovered in 2017. Within it, an almost completed block and the tools used for cutting it had been uncovered: hardened arsenic copper chisels, wooden mallets, ropes and stone tools. In the experiment replicas of these were used to cut a block weighing about 2.5 tonnes (the average block size used for the Great Pyramid). It took four workers 4 days (with each working 6 hours a day) to excavate it. The initially slow progress sped up six times when the stone was wetted with water. Based on the data, Burgos extrapolates that about 3,500 quarry-men could have produced the 250 blocks/day needed to complete the Great Pyramid in 27 years.