Another North African mathematician, al-Hassar, about the same time developed the modern way of writing fractions, with a bar separating the top from the bottom, like 1/2 or 2/7. Al-Hassar also wrote textbooks in Arabic about how to add whole numbers and fractions, how to calculate square roots and cube roots, and prime numbers
By 3000 BC, people in Egypt were using hieroglyphs to write down very large numbers.