The Egyptians knew the basic mathematical functions and could perform practical calculations. They did not understand abstract mathematics and did not develop formulae to solve practical problems. They used a decimal system, but were limited with fractions. Except for 2/3, they used no numerators greater than 1. Arithmetic problems had to be solved by several small calculations, for which they had tables. For multiplication and division, there were also tables.
They had some understanding of the principles of geometry. They were aware that a right-angle triangle could be made in the ratio of 3:4:5. However, they had nothing to express the concept of the Pythagorean theorem. They could calculate the area of a triangle and the volume of a pyramid. They came close with their method of measuring the area of a circle. They took 8/9 of the diameter and squared the result.
Despite these limitations, they showed great skill in technology with the building of pyramids and temples in their superior craftsmanship. These required accurate measurements, using rather primitive tools.