Ancient Egyptian civilization left behind architectural achievements that could not have been constructed without mathematical calculations. The Egyptian mathematical papyri bear witness to this. The way of thinking at that time was always additive and focused on reconstructing the whole. Fractions are based solely on unit fractions. To make it easier to combine unit fractions, tables were created, and in addition example problems were written down in a kind of formulary, e.g., the Rhind Mathematical Papyrus. This additive approach is explained using a few examples and applied to current problems in mathematics and computer science.