How to Multiply Like the Ancient Egyptians
The ancient Egyptians were probably one of the first civilizations to have a form of mathematics which influenced most of our mathematical traditions to date. We know that they used an approximation for Pi, fractions, a decimal system and a system to multiply and divide numbers. To multiply like the ancient Egyptians, you only need to use progressive doubling and addition.
- Difficulty:
- Easy
Instructions
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1
Use the Egyptian method to multiply 54 X 75.
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2
Make a table with 2 columns.
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3
Label the left hand column A and the right hand column B. Under column A, write down the number 1. In column B write down the number 75 (one of the numbers of the multiplication).
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4
Double the numbers in each column over and over until you get to a number that is just below 54 (the other number of the multiplication) in the left hand column A. Write these down in each column. For column A you get the numbers 1, 2, 4, 8, 16, 32 while in column B you should get 75, 150, 300, 600, 1200, 2400. Note that we stop the doubling process at 32 which is just below 54. You should have 6 numbers in column A and correspondingly 6 numbers in column B.
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5
Mark the numbers that add up to 54 in column A. These are 2+4+16+32=54. Now add the numbers in column B that correspond to these numbers and you get 150+300+1200+2400= 4050 which is the answer to our multiplication problem.
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6
Check the answer by multiplying 54 X 75.
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1
Tips & Warnings
You can also start with 54 in column B and with 1 in column A but stop doubling when you get to a number that is just below 75 in column A. Follow the procedure in this tutorial and you get the same answer.
