Pyramids were built in Ancient Egypt as tombs, or burial places, for Egyptian pharaohs, or kings. They believed that the pyramids made you immortal. The Ancient Egyptians believed in an afterlife, so it was very important to them to protect the bodies of their pharaohs.
CaCO3, or calcium carbonate, has a molar mass of 100.09 grams per mole. This means there are roughly 566 grams of CaCO3.
number of molecules = number of moles * avogadro's number. so indeed you have 0.100 mol CaCO3, and from stoechiometry it shows you have indeed 0.100 mol of CO2, but the number of molecules is not correct yet..