Egyptian Mathematics By Edwin Barnes 7 Kolbe St Joseph’s Catholic and Anglican School Egyptian Number Symbols The Egyptians didn’t use numbers like we do, they used symbols to represent the numbers instead. 10000 100 000 000 =1 000 symbolsfor reflect everyday one may come The symbol geta ten more thousand hundred million thousand is ais is aa Egyptian things. is a fromcalled alily. finger. Everyone starts complicated water finger. thousand god Perhaps It isHeh. shows aas frog, the itItThis isalso the sometimes numbers a symbol finger leaf, means ten coil of rope. off counting on but their fingers! geta stem thousand as just bigger. atadpole. and very times root, large The symbol as number, not big the as forlike the ten is a piece flower. symbol 'squillion'. forofone! rope. Numbers In thisthe system is better To some make aways, number, Egyptians would than write ours because if we want to write the number one down the symbols in order of largest to smallest million, have seven digitsFor to write, but the from left we to right to form groups. example: Egyptians only had to write one. = 22 But the downside of the system is that if they wanted to =write 7 the number one less than one million, 999,999, they would have to write 9 one hundred thousands, 9 ten thousands and so on down to 9 ones, using a massive total of = 266 54 digits! Addition The of addition was veryAddition. simple Thismethod is an example of Egyptian They collected together the symbols that were the same from both of the numbers If there were ten of the same symbol, it could then be substituted for the symbol higher up in value Subtraction To subtract a number, the Egyptian would write down the two numbers, and then take away the symbols that appeared in the second one from the first one. For example: Subtraction This is, however, complicated when more of a symbol are to be taken away than there are present, for example 63 - 48 In this case, they would convert one of the tens into ten units, and use it to complete the calculation, for example: Multiplication And this column They drew a table like this: The Egyptians used quite a complex is the number in the firstwould column find The Egyptians method of multiplication. This multiplied by 12 column is the numbers in the first the use the example of 12 x 17 Weallwill columnIt isthat add up to 17, POWERS easy to complete these OF TWO which columns is 1 + 16 because, as you are only using powers of Then they would find the two, each number is the number above it doubled multiples of 12 which correspond, and add them together like so: Division They Division in Ancient required would draw theEgyptian “powerstimes of two” table the useagain, of multiplication and often3 involved but this time using They then found the fractions. They would keep corresponding goingscribes until 42 could This is because the Egyptian powers of 2 and made in theto right added recognised them that division isbethe inverse together to find the column multiplication, and used that fact to help answer them work out divisions They didn’t divide as we would, but asked themselves a x ? = b (instead of a / b = ?) We can use the example 42 divided by 3. Fractions an example of an Egyptianused Fraction Here Theisfractions that the Egyptians were not so different to ours, except that they were This symbol represents limited to the use of unit fractions, which are a “part”. It is like the numerator, but always fractions that have a numerator of 1. means 1 The fractionsThis they use do not have a represents the fraction ½ numerator and a denominator, they are made up of a number and then a “mouth” symbol This is the denominator on top of it. Fractions There are some rules about expressing fractions as a sum in this way: If an Egyptian wanted to write a fraction 1. When a fraction can be expressed in more than with numerator of more than one,the such one aform, use the form which requires least as ¾, ⅔ of orunit ⅜, then they would have to number fractions. it asthe several fractions added 2. express Always use largest unit unit fraction possible unless this means that the previous rule cannot together. For example: be complied with. 3. No unit fraction may be used more than once in an expression, so you can’t write ⅔ as ⅓ + ⅓ 4. Write the unit fractions in order of size from largest to smallest. The Eye of Horus TheEach Eye of Horus an iconic part of theisEye represents a fraction symbol often associated with Ancient Egypt and its mathematics. Each fraction is half the one before it, The name from the Egyptian andcomes the fractions keep going on, God of mathematics, getting smallerHorus. and smaller It represents the basis of Egyptian The ideathe is that, if you go on forever mathematicsunit fractions. and then the you ancient add all the fractions It also symbolizes together, eventually you’ll get to 1 mathematical concept of infinity The Eye of Horus For example: At this point, we reached a total of 8191/8192, or 0.9998779296875, which is very, very close to 1, but not quite there. The more fractions you add on, the closer you get to 1, but you will never actually reach 1 unless you carry on to infinity Units of Measurement 1 Palm used their own body to The Egyptians 1 Digit measure things around, which often meant that measurements were not very accurate or consistent 1 Cubit Thank you for watching my presentation By Edwin Barnes 7 Kolbe St Joseph’s Catholic and Anglican School