The ancient Egyptian numerals system was based on the number ten.It was not a fully developed decimal system like the one we use today.
They had different hieroglyphic symbols that marked one,ten,a hundred,a thousand,ten thousand,a hundred thousand and one million.The rest of the numbers were simple to write.For example,if they wanted to write 4 they would just repeat the symbol for one four times.The same went for 10,1000 and so on.
Sometimes the numbers were expressed phonetically,e.g. 'twenty' instead of '20', but this was only common for one and two.For the rest of the numbers it was rather rare.
Take a look at the image below with the core symbols of the ancient Egyptian numeric system.
The Egyptian hieroglyphic alphabet
Neter-God king in hieroglyphics.