Egypt was the richest part of Africa, so Egyptians could afford to educate a lot of people and there were a lot of scientists in ancient Egypt. These Egyptian scientists were especially interested in medicine, engineering, and irrigation. The pyramids and temples, for example, show good knowledge of geometry and engineering. Egyptian engineers used the Pythagorean theorem (thousands of years before Pythagoras was born) to figure out distances without measuring.
Because the Nile flood was so important to Egyptian farming, Egyptian scientists also worked out good ways to measure how high the flood was going each year. They kept accurate records and good calendars. You can see here how the Egyptians wrote down numbers. We call the device they used to measure the height of the Nile flood a Nilometer (ny-LA-muh-terr).
Egyptian doctors were also considered the best in the ancient Mediterranean. They figured out how to set broken bones, pull out infected teeth, and massage aching muscles. They could fix dislocated elbows and shoulders. And Egyptian doctors did a lot of early research into how the human body worked.
It may also have been Egyptian scientists who first figured out how to make wheat and barley into beer and yeast-rising bread. By the time of the Ptolemies, Egyptian scientists worked out ways to hatch goose and chicken eggs in giant factory incubators. That made roast chicken cheaper.