 The ancient Egyptians used two different systems to write numbers. On permanent surfaces, like stones, they used hieroglyphics. Each symbol represented a specific value. So a single vertical mark represented one. An inverted loop would represent ten. This spiral hieroglyph would represent a hundred. A lotus plant, or Audrey, a thousand. A tadpole ten thousand, and a bird a hundred thousand. To represent higher values, multiple copies of the symbols were set down. For example, in something like this, we see there are four ones, two tens, and three hundreds. And so we would read this number as three hundred twenty four. Because the value of a number depended on the sum of the values of the symbols, we say this system is additive. One of the advantages of writing on stone is that material lasts for a very long time. And so this image shows a steeler, a commemorative marker, like a gravestone, of Mentuoser, a steward, a manager, who died around 1944 BC. So four thousand years later, we can read something about his life. At least if you can read hieroglyphics. Well, we can at least read some of the numbers. So if you take a look in this upper right-hand corner, we see this number, which is a ten and three ones, or thirteen. And if we look down towards the middle of the tablet, we see three one thousand symbols. So this represents the number three thousand. On less permanent surfaces, the Egyptians used hieratic. This was also a form of additive notation, but it required more symbols. So forms changed over time, but reasonably common forms for one through nine were these. For ten through ninety, they used these forms. And one hundred through nine hundred looked like this. So to read this number, we'll figure out this first symbol. And if we look at our table, we see that it's an eight. Our next symbol looks to be a forty. And our last symbol is a three hundred. And so we might read this number as three hundred forty eight. The hieratic numerals were suitable for day-to-day use, and these were the things that you wrote with when you had to record accounts or do business or do anything useful. Unfortunately, because they're written on much less permanent material, what we have left is very fragmentary. And so here we see the fragment of what appears to be an inventory of bulls and beer also written around 1970 BC. And let's see if we can read some of the numbers. So we can see many instances of the numbers two and three. And if we look elsewhere, we can see the numbers five and ten. And if we look around, we can actually find a symbol for hundred as well.