 Ex. 8. Answer the following questions.

1. What numerals were used in Europe until XVI century? 2. Who introduced the symbol 0? 3. Is the Hindu-Arabic system a decimal system or a binary one? 4. What does the value which a digit represents depend on? 5. What are the signs most used in arithmetic? 6. What are the fundamental operations of arithmetic? 7. Are division and multiplication inverse operations? 8. Are subtraction and multiplication inverse operations? 9. What must you remember about multiplication? 10. What important facts about division must be remembered?

Ex. 9. Find the Russian equivalents for the following English word combinations.

1. to use the same numbers; 2. to represent numbers; 3. present notation; 4. numeration system; 5. decimal system; 6. to be based on tens; 7. inverse operation; 8. capital letters; 9. arithmetic sentence; 10. to measure the distance

a. основываться на десятках; b. обратная операция; c. заглавные буквы; d. измерять расстояние; e. десятичная система; f. представить числа; g. использовать одни и те же числа; h.система счисления; i. арифметичес­кое выражение; j. современная система записи

Ex. 10. Mark the following as True or False.

1. People used numbers thousands of years ago. 2. The decimal number system was invented by the Romans. 3. The Roman system of numbers is based upon the letters A, B, C, D, E, F and G. 4. The symbol 0 was introduced by the Arabs. 5. The work of a zero is to keep the other nine symbols in their proper place. 6. Our decimal number system is positional. 7. We go from right to left in forming larger and larger units of ten, hundred, thousand and so on. 8. We work both with positive and negative numbers in arithmetic. 9. The product of any number multiplied by one is the same number. 10. The quotient is 0 whenever the divisor is 0.

Ex. 11. Fill in the blanks with necessary words and word combinations from the box.

 the sum, the quotient, the multiplication sign, to divide, the difference, subtraction, factors, addends, the subtrahend, a remainder, to be added, a numeral, division

1. We get … as a result of addition. 2. The numbers to be added are called …. 3. You may check … by multiplication. 4. Will there be … if you divide 25 by 7? 5. If you are … two numbers, you must remember that division by 0 is meaningless. 6. To find the minuend … and the subtrahend must be known. 7. Addition and … are inverse operations. 8. The multiplicand and multiplier are the names for the … . 9. The result of division is known as …. 10. The difference is the number that when added to the … gives the minuend. 11. The plus sign between two numbers means that these numbers are … . 12. A dot placed between two numbers is used as … . 13. A symbol used to represent a number is called … .

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