Sunday, February 10, 2008

Napier Multiplication strips.

The well known Scottish Mathematician, John Napier prepared a device around 1617, which was used to multiply. He called these strips as "Bones". In this article we are going to explain you how to prepare and use it in your class room teaching.


Material Required :

1. A big sheet of thin cardboard

2. White papers

Steps of Construction:

1. Paste the white board on the sheet of cardboard.

2. Cut nearly 50 strips of size 20 cm x 2 cm from the cardboard.

3. Mark the line to divide the strips into 10 squares of side 2 cm.

4. Mark the diagonals of the each of the squares on every strips as shown in the below figure.


5. Writedown the tables of the numbers from 0 to 9 as shown in the figure.

6. Prepare at least 5 strips for each table.

Working:

Suppose you want to multiply 7859786 x 4


Procedure:


1. Arrange the table strips in the order of the digits of the multiplicant (7859786) as shown in the figure.


2. Select the 4th row (since multiplier is 4).

(In the ascending order of the place value.)


3. Add the numbers diagonally from right to left, incase, you get sum as two digit number in any diagonal then carry its 10 digit to the next diagonal.


Use:

It can be used as teaching aids for class room teaching as well as Maths Laboratory.