Subject Area Lessons

## #1695. Egyptian Multiplication

Mathematics, level: Middle
Lesson Plan
IUP, Indiana, PA
Materials Required: None
Concepts Taught: Upon completion of lecture on Egyptian Multiplication, these ninth

This lesson plan will be about a new type of algorithm that will help those of you with problems
multiplying numbers. This algorithm is entitled Egyptian Multiplication. This method was used and
developed by the ancient Egyptians. These were people who migrated from the fertile Sahara region of
Africa. The Egyptians had customs similar to those of the Ethiopians. The Egyptian civilization was one
of the greatest ancient civilizations. They were well organized and one of the more advanced of the
ancient civilizations. They had calendars, standard weight and measure system and a centralized
government.
Egyptians used a different way to write the numbers than we do. Their writing is called hieroglyphics.
This type used different pictures to stand for different numbers. The list that follows is what these
hieroglyphics look like:

Egyptians had an interesting way of doing multiplication. They used addition to get the answer of a
multiplication problem. They only had to memorize one multiplication table. That table would be the 2
times table. This method is still used in many rural communities in Ethiopia, Russia, the Arab World, and
the Near East.
The term that we use with Egyptian Multiplication is called Doubling. Doubling does just what it
sounds like. You take one number and either multiply it by 2 or you add it to itself. This is done
repeatedly until you get the other number. Below is an example of what you need to do using the
problem 22 x 21:

You first take either number, the 21 or 22. Here we used the 22. Then set up a little chart like we
have done. Put the number being doubled on the right hand side. On the left hand side you put the
"double number". You keep putting the corresponding double with the number that was doubled. Once
you get to a double larger than the other number you are multiplying then you can stop. Now you have to
find the double numbers that add up to the other number, in our case is 21. The doubles that add up to
21 are 1, 4, and 16. Take the corresponding numbers and add them together; 22+88+352=462. That
number is the product of 22 and 21. Below are some more examples:

After completing these examples with the help of the class. I would then ask them for some number
that they would like to see multiplied together using this method. We would do these together with the
class telling me the doubles of the number. After about 10-15 minutes of this activity, I would then ask
them for five more pairs of numbers that they want multiplied. Once I write the numbers on the board, I
would tell them to copy these down and do them for homework that would be collected tomorrow in class
and is worth the same amount as a quiz. Before our departure, I ask them if they have any questions. If
so, I would answer them. I also remind them if they need extra help I would stay after school for about 2
hours. 