Skip to main content

DOUBLING IS THE BEST WAY

  


                    ADVT:  HOME PROJECTOR IN AMAZON

   1. CODE   

Double the number as follows

      1,  2,  4, 8

     = 2^0,  2^1,  2^2,  2^3

Now reverse them as  8 4 2 1


Now code as follows

8    4   2   1

0    0   0   0   represents  0

0    0    0  1   represents  1

0    0   1   0   represents  2

0    0   1   1  represents   3

0     1   0   0  represents 4 

0     1   0   1  represents  5

.....    ....  ...   ....      ......

.... .....     ....     ..      ......

1   1   1    1   represents 15

8 4 2 1 code can represent up to 15. But 0 to 9 is enough to represent all numbers.

            8  4  2  1             8  4  2  1          8  4  2  1

345  =   0  0  1 1(3)        0  1  0  0(4)     0  1  0  1(5)

this code is used in digital gadgets.


2. Weights:

    In those days, weighing stones were used by traders.  To measure up to 255 kg, the following weights are enough.

1,2,4,8,16,32,64,128

         (doubling way)

To weigh 153 kg, use

128+16+8+1 =153

You can try any other weight.

3. Doubling money:

   Normally, coins and notes in the following denominations are in circulation.

1,2,5,10, 20,50,100,200,500,1000, 2000

Here, instead 4, five is used. So, it will be practical and round one.  Now the transaction and trading will be easy with those banknotes and coins.

4. Egyptian Multiplication:

  We want to multiply 13 and 7. Let 13 be the multiplicand and 7 be the multiplier.  Now, write doubling numbers in one column up to multiplicand and not exceeding the multiplicand.

  1

  2

  4

  8

Not 16, it exceeds 13.

   In the next column, start with multiplier and double it every step.  

Multiplicand     multiplier

   1                               7

   2                              14

   4                              28

    8                             56

In the first column, if you add 1+4+8 = 13, we get the multiplicand. In the second column, add the corresponding numbers, you get the answer 91  (7+28+56).

Principle:  We want 13 times7. Adding 1 times 7, 4 times 7, and 8 times 7, we get 91 which is 13 times 7.

   Egyptians practiced this kind of multiplication in 2000 BC.  How smart they were!    

Comments

Popular posts from this blog

THE EARTH, A SUPER ORGANISM

     JOIN MY COURSE: "Become a programmer in a day with python"       A man called 'love lock' (what a name) proposed a theory called Gaia theory, named after Greek Goddess.      It says, "Earth is a self-regulating organism like a human being.  The organic life in it interacts with in-organic matter and maintains atmosphere, temperature and environment".  Hence the earth is still suitable for the life to thrive.      Imagine, in a particular place, there are lot of flowers.  Some flowers are white and some are darkly coloured.  We know, white reflects light and heat while dark absorbs the same.  White flowers can thrive in hot climate.  But dark flowers requires cold climate.  The absorption and reflection balances and the environment reaches average, warm temperature at which both the flowers can co-exist.  This is the essence of "Gaia" theory.      On our earth, ...

THE PARABOLA

          A jet of water shooting from a hose pipe will follow a parabolic path.  What is the so special about parabola.    Y= x^2 Draw a graph for the above equation.  It will result in a parabola.  This parabola is also called unit parabola.  Any equation involving square will yield a parabola. Example:  Y = 2x^2 +3x+3 (also called quadratic equation)    X= 2 and -2, both  satisfies the equation 4 = X^2.  Parabolic equations always have two solutions.     Any motion taking place freely under gravity follows parabolic path. Examples:   An object dropped from a moving train,   A bomb dropped from flying plane,  A ball kicked upwards.      If a beam of light rays fall on the parabolic shaped mirror, they will be reflected and brought to focus on a point.  This fact is made use of in Dish Antenna, Telescope mirrors, etc.   ...

DISORDER IS THE "ORDER OF THE DAY"

         Imagine a balloon full of air.  The air molecules are moving randomly inside the balloon.  Let us pierce the balloon with a pin.  The air rushes out.  Why should not the air molecules stay inside the balloon safely and ignore the little hole?  That is not the way the world works.  The molecules always "want to occupy as many states as possible".  Hence the air goes out in the open to occupy more volume.   The things always goes into disorder (entropy) and the disorder increases with time.  The above statement is what we call "second law of thermodynamics".      Consider a cup of coffee on the table. Suppose the heat from entire room flows to your cup of coffee, the coffee will boil and the rest of the room will freeze.  Freezing means bringing things to order and arrangement.  It violates the second law.  Hence it will never happen.  Hence heat must flow from high ...