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5.05010301

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Trlx hoex erfa eetb mpet. This is the message that shook Europe for one hundred days. Had it been intercepted and read, the course of the history might have been different. But this message reached its destination, and Napoleon Bonaparte was able to land safely in Marseile while his enemies were napping.

Naturally, such message had to be so disguised that only a few trusted persons could read it. Messages that are written in such a concealed manner are said to be "in code", and the process of reading coded messages is known as decoding.

In order to decode a message the secret of its arrangement or the key of the code must be known. This is the same key which is used by a person when he translated his message into a coded one.

Generally, the key of a code is a secret which is closely guarded by the sender as well as the recipient of the coded message. However, sometimes the secret of the code may be discovered through observation and reflection. Let us take the above message. We observe that the entire message was broken up into five groups of four letters each. This alone does not give us a clue. However, we note that first letter of each group, if removed from the coded message and written all together T h e e m, may mean something. This may be an important clue. Consequently, we try the same thing with the second letters of the groups. We obtain r o r e p. If we examine the combination of these five letters we may observe that the reversal of their order yields peror. Thus the first two trials yielded the emperor.

The third set of letters gives "lefte", and the fourth set of letters, which is again written backwards, is x x a b l. Reversing the order of the fourth set of letters yields l b a x x. Now, assembling our findings, we have: THE EMPEROR LEFT ELBA xx

 

 

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Nature thoughtfully provided our earliest ancestors with a simple aid of computation- a digital computer in the strictest sense of the word- copies of which may be seen in active use in any school-room where the youngest generation is counting on its fingers. In making this provision, nature unwittingly established the decimal base, with its 10 digit values as a natural mode in which the human race might express its numerical ideals.

In the beginning - to borrow a phrase - there was the abacus. This little device came into being some 2,000 years ago and still is the most widely used calculator on earth. In some areas of the world it is the only known counting device.

The word calculation itself came from the earliest form of abacus which consists of lines drawn on the ground, with small limestone pebbles to represent numbers. Latin word calcis means lime or limestone and the Latin word calculus, which grew out of it, first meant a small piece of limestone and later was expanded to mean any pebble used in counting.

The abacus (from abax, an ancient Greek word for stab) was a direct result of early efforts to count. When primitive man satisfied his need for food and shelter, he began seeking ways of expressing himself. His first writings were the rudimentary drawings on cave walls, the notches on the trees. The earliest were simply representation of what we find in nature - the sun, the moon, the animals he hunted. Soon, however, he wanted to express how many animals he had killed in a hunt, how many children he had, and so forth. Such was the development of symbols to indicate one, several, and many.

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