EGYPT
History
 

1. ANCIENT EGYPTIAN CIVILISATION

The ancient Egyptian civilisation developed on the banks of the Nile about four thousand years before Christ. We have been able to learn about their system for recording words and numbers by using hieroglyphic symbols from papyrus manuscripts. Although the Babylonian tablets survived for so long so well, this wasn't the case with the papyrus documents. However, understanding the system has been made much easier since the discovery of the Rosetta Stone in 1799. This large tablet is inscribed with text written in three different scripts: Greek, Demotic (the local language) and hieroglyphs. This allowed hieroglyphs to be translated into Greek and then into other languages. The most important mathematic document to have been discovered is the Rhind Papyrus (named after the  Scottish antiquary who found it in 1858) or the Ahmes Papyrus (as it is also known, named after the scribe who copied it in about 1650 B.C. The material appears to have belonged to the Middle Kingdom (2000 to 1800 B.C.) and some of its knowledge may have come from Imhotep, who was the architect in charge of the building of Pharaoh Zoser's pyramid about 5,000 years ago. Other papyri of great importance are the Kahun Papyrus, the Berlin Papyrus and the Moscow Papyrus. The Rhind Papyrus and the Moscow Papyrus both contain examples of mathematical problems. The table below reflects the extent of mathematical knowledge during ancient Egyptian civilisation. It is important to bear in mind that the Egyptians used mathematics to solve everyday problems (e.g. to survey the land by the Nile which was often flooded when the river burst its banks and to construct pyramids). All the examples refer to specific cases, concrete shapes with fixed measurements, which are descriptive but do not include what we nowadays refer to as proof. These particular examples were probably used as teaching material at the time.

Hieroglyphic script 

Left: The Rhind Papyrus inscribed with hieratic script 1650 B.C. 

 

 

Right: The Moscow Papyrus

Number theory
  • Whole fractions and 2/3
  • Addition, multiplication and division using the duplication process and the "rule of three".
Algebra
  • Algebraic problems which are solved using the "method of false position". The unknown is referred to as a heap: 
  • Problem 24: Work out the value of the heap if the heap and a seventh of the heap is equal to 19.
  • Solution: Choose a possible value for the heap, e.g. 7, carry out the operations and you get 8 as an answer. Compare 8 to 19 and you see that you have to multiply 8 by (2+1/4+1/8) to get 19. In the same way multiply the brackets by 7 to get the value of the unknown heap. Finally show that 7·(2+1/4+1/8)=16+1/2+1/8, which is the value of the unknown heap. As you can see, only unit fractions are used.
Geometry
2.- PROBLEM 51

The area of an isosceles triangle is equal to the area of a rectangle whose base is half that of the triangle and whose height is the same as that of the triangle.

1.- You can see how this theory is proved in this window.
Change the size of the shape by dragging the pink points with the left-hand button on the mouse.

If you click on the right-hand button on the mouse a menu will appear which gives you the option of animating the demonstration, changing the dimensions of triangle abc, altering the scale and translating the image.

Watch the different steps of the animation by using the controls in the lower part of the window, which appear once the demonstration has been activated.


3.- PROBLEM 52

The area of an isosceles trapezium whose larger base is 6, smaller base is 4 and the distance between them is 20, is equal to a rectangle with the same height but whose base is half the sum of the trapezium bases.

1.- The dimensions of the trapezium are those which appear on the papyrus. Chose different ones to see it more clearly.

At the end of the animation see if you can find the relation between the bases of the trapezium and the rectangle.

Change the size of the shape by dragging the pink points with the left-hand button on the mouse.

If you click on the right-hand button on the mouse a menu will appear which gives you the option of animating the window, changing the dimensions of the trapezium, altering the scale and translating the image.

Watch the different steps of the animation by using the controls in the lower part of the window, which appear once the demonstration has been activated.

4. A DIFFERENT SOLUTION TO THE PROBLEM

 The area of an isosceles trapezium is equal to half the area of a parallelogram whose base is the sum of the bases of the trapezium and whose height is the same as that of the trapezium. 

 1.- This diagram is more intuitive but requires the use of a parallelogram. However, the Egyptians didn't make use of these shapes.

At the end of the animation see if you can find a relation between the bases of the trapezium and the rectangle.

Change the size of the shape by dragging the pink points with the left-hand button on the mouse.
If you click on the right-hand button on the mouse a menu will appear which gives you the option of animating the window, changing the dimensions of the trapezium, altering the scale and translating the image.
Watch the different steps of the animation by using the controls in the lower part of the window, which appear once the demonstration has been activated.

5.- PROBLEM 48

This problem gives an idea of how the Egyptians used to work out the area of a circle by using a method of approximation.

In problem 50 the area of a circle with a diameter of 9 units is equal to a square with a side of 8 units. This gives us an approximation of the number PI.

PI=3.16=3+1/6

The method they used is illustrated in this window.

1.- An octagon is used. The method has several stages:

Draw a circle

Draw a square whose side is equal to the diameter of the circle.

Divide the side into three equal parts and keep the central segment.

Cut off the four corner isosceles triangles to obtain an octagon whose area is close to that of the circle.

In this window you can see the calculation that are made and compare the approximate results given to the actual results.

 Numerical notes

 

 As well as these methods of approximation the Egyptians also made use of one of the properties of curvilinear shapes which is undoubtedly accurate, from which we obtain one of the first exact statements in the history of mathematics. This statement is as follows: The ratio of the area of a circle to the circumference is equal to the ratio of the area of the circumscribed square to its perimeter.

       
           
  Rosa Jiménez Iraundegui
 
Spanish Ministry of Education. Year 2001