14, 15 с объяснением
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The Romans used a counting table, or abacus, in which units, fives, tens and so on were represented by beads which could be moved in grooves. They called these beads calculi, which is the plural of calculus, or pebble. We see here the origin of our word calculate. In the Chinese abacus, the calculi slid along on rods. In Chinese, this kind of abacus is called a suan-pan; in Japanese it is known as the soroban and in the Russian language as the schoty. The operations that could be rapidly done on the abacus were addition and subtraction. Division was rarely used in ancient times. On the abacus, it was often done by subtraction; that is to find how many times 37 is contained in 74, we see that 74-37-37, and 37-37-0, so that 37 is contained twice in 74. Our present method, often called long division, began to be used in the 15 century. It first appeared in print in Calandri's arithmetic, published in Florence, Italy, in 1491, a year before Columbus discovered America. The first machines that could perform all the operations with numbers appeared in modern times and were called calculators. The simplest types of calculators could give results in addition and subtraction only. Others could list numbers, add, subtract, multiply and divide. Many types of these calculators were operated by electricity, and some were so small that they could be easily carried about by the hand. the twentieth century was marked by two great developments. One of these was the capture of atomic energy. The other is a computer. It may be rightly called the Second Industrial Revolution. What is a computer? A computer is a machine that can take in, record, and store information, perform reasonable operations and put out answers. Such a machine must have a program, and specialists are needed to write programs and operate laboratories, museums, libraries, hospitals and shops, ... the system... transportation and communication. You can see that there is practically nothing ... our modern life which is not based mathematical calculations. ... co-operation ... science, mathemat made possible our big buildings, railroads, automobiles, airplanes, spaceships, subways and bridges, artificial human organs, surgical operations and means of communication that in the past seemed fantastic and could never be dreamt ... ... Text Comprehension 9. Answer the following questions: 1. What is the text about? 2. What signs did people use instead of numerals? 3. What is the role of numerals in our life? 4. What numbers sound alike in many languages? 5. What number names is the word digit applied to? 6. How long has it taken people to learn to use numbers? 7. What is a numeral? 8. How did the first arithmetic book appear in Europe? 9. What numbers were the most important for people in the remote past? 10. What devices did they invent to make computation easier? 11. What operations were done on the abacus? 12. When did long division appear? 13. What were the first counting machines called? 14. Could they perform all basic operations of arithmetic? 15. What development was the next step in counting?
