RULE FOR READING NUMBERS. RULE. Divide the number into periods, and read the periods in succession, beginning at the left, giving the name of each period except the last. EXERCISES. 1. How many periods in the number 723415? 2. How many periods in 12384767? How many orders? 3. How many thousands in 925682? 4. How many ten-thousands in 72841? In 74081? 5. What orders are filled with ciphers in writing: Twelve hundred and five? Sixty-one thousand and six? Four hundred thousand and one? Nine hundred and forty-nine? One thousand and one? 26. Numeration is the art of reading numbers when expressed by written characters. 27. Each removal of a significant figure one place further to the left multiplies the value expressed by it by ten. 28. Each removal of a significant figure one place further to the right divides the value expressed by it by ten. 29. There are two methods of reading numbers by periods. a. In the French Method a period consists of three orders. b. In the English Method a period consists of six orders. In the French Method the scale of the period is one thousand; that is, any order of one period is one thousand times as great as the corresponding order of the next lower period. Thus: Ten million is one thousand times as great as ten thousand; ten billion is one thousand times as great as ten million. In the English Method the scale of the period is one million; that is, any order above millions is one million times as great as the corresponding order of the next lower period. Thus: Ten billion is one million times as great as ten million; ten trillion is one million times as great as ten billion. 30. In both the English and the French systems the names of the corresponding periods above quadrillions are the same. The French system of reading numbers is the one commonly used in this country. ROMAN SYSTEM. 31. In the Roman System numbers are expressed by means of letters. These seven characters are given below: Values: one. five. Letters: I. V. one five one ten. fifty. hundred. hundred. thousand. D. XXX. Thus : I. II. III. X. XX. II. The value of a letter written after one of greater value, is added to the greater value. six. eleven. fifteen. sixteen. sixty. Thus : VI. XI. XV. XVI. LX. III. The value of a letter written before one of greater value, is taken from the greater value. four. nine. Thus: IV. IX. forty. ninety. IV. The value of a letter written between two letters of greater value, is read in connection with the letter following it. nineteen. fifty-nine. fourteen. Thus: XIX. LIX. XIV. V. A dash placed over a letter increases its value one thousand times. M one million. EXERCISES. 1. Write eighteen hundred and eighty. 2. Write seventeen hundred and seventy-six. a. DEFINE GENERAL REVIEW. 1. Arithmetic. 2. Mathematics. 3. Quantity. 6. Abstract number. 1. Scale. 2. Period. 3. Order. b. NAME 12. The fundamental rules. 14. Characters used in each. 21. The periods in each 22. Number of orders in each period. C. STATE THE DIFFERENCE BETWEEN 23. The simple and the local value of a digit. 24. The French and English systems. 25. The scales of the two systems. 26. The names of the periods in the two systems. 27. The Arabic and Roman systems of notation. ADDITION. 32. Addition is the process of finding the sum of two or more numbers. The sum of several numbers is a single number which expresses as many units as all the numbers added. 33. Only like numbers can be added. Like numbers are such as express the same kind of unit; as, 3, 4; $3, $4; 3 yds., 4 yds; 3 pecks, 4 pecks; 3 tens, 4 tens; 3 hundreds, 4 hundreds. 34. The Sign of Addition is +, called plus, and denotes that the numbers between which it is placed are to be added together. The sign =, called the sign of equality, indicates that the several numbers which precede it, taken together, equal the number which follows it, called their sum. ORAL EXERCISES. 1. Two units and three units and four units and one unit make how many units? |