Arithmetic

TEXT

How the use of numbers began

Many thousands of years ago this was a world without numbers. Nobody missed them. Everyone knew just what belonged to him and what not. If a cow was missing, the owner knew it was gone, not by counting cows, but for the same reason your mother would know if you did not come home for dinner.

But some people acquired more and more property. They would count¹ one cow, two cows, three cows; one vase, two vases and three vases; always one, two, three or more of something they owned or saw.

How far we have advanced from the time of our ancestors! Today, using numbers, numerals and mathematics, man builds bridges, skyscrapers, flies off the earth like a bird, even measures the distance to the moon and the brightness of the light given off by the firefly. But just as important² thought not so exciting, is that he can tell the time, pay the grocer, count the runs in a baseball game and use the same numbers in many different ways in everyday life.

So you see, mathematics and numbers, from simple arithmetic to complex algebraic and geometric calculations, are important to life in our time.

Roman Numerals. The Romans used seven capital letters to represent numbers³. They mixed them together to form many different combinations.

The Roman system of numbers is based upon⁴ the letters, I, V, X, C, D and M. This is what each letter represents:

Roman Numeral	I	V	X	L	C	D	M
Hindu-Arabic Numeral	1	5	10	50	100	500	1000

Notes:

¹ they would count – они обычно считали

² just as important - так

³ to represent numbers – для обозначения чисел

⁴ to base upon – основываться на

Exercises

I. Read the following words paying attention to the pronunciation:

acquire, advance, ancestors, skyscrapers, firefly, exciting, brightness, light, algebraic, geometric.

II. Form nouns of the following words:

to count, to advance, to use, to build, to fly, to pay, to represent.

III. Form adjectives of the following words by adding the suffixes -full, -less, -able and translate them into Russian:

use, need, reason, count, represent.

IV. Answer the following questions:

1. When did people begin to count? 2. For what purposes do we use numbers? 3. Why are mathematics and numbers important? 4. What letters did the Romans use to represent numbers?

V. Translate into Russian:

Primitive man knew only ten number-sounds. The reason was that he counted in the way a small child counts today, one by one, making use of his fingers. The needs and possessions of primitive man were few: he required no large numbers. When he wished to express a number greater than ten he simply combined certain of the ten sounds connected with his fingers. Thus, if he wished to express "one more than ten" he said "one-ten" and so on.

VI. Make up sentences of your own using the words and expressions given below:

acquire, property, advance, measure, important, calculations, for the same reason, just as important, to make use of, in everyday life, in the same way, in a different way.

TEXT