Explanation of Characters used in this Book Equal to, as 12d. 1s. signifies that 12 pence are equal to shilling. + More, the sign of addition, as 5+7=12, siguities that 5 and 7 added together, are equal to 12. Minus, or less, the sign of subtraction, as 6-2=4; signifies that 2 subtracted from 6, leaves 4. Multiply, or with, the sign of Multiplication; as 4x3=12, signifies that 4 multiplied by 3, is equal to 12. The sign of Division; as 8÷2-4, signifies that 8 divided by 2, is equal to 4; or thus, 4, each of which signify the same thing. :: Four points set in the middle of four numbers, denote them to be proportional to one another, by the rule of three; as 2:4::8:16; that is, as 2 to 4, sn is 8 to 16. ✔ Prefixed to any number, supposes that the square root of that number is required. Prefixed to any number, supposes the cube root of that number is required. Denotes the biquadrate root, or fourth powes, &e, 18 ARITHMETIC. ARITHMETIC is the art of computing by numbe and has five principal rules for its operation, viz. Numeration, Addition, Sabtraction, Multiplication, and Div. sion. NUMERATION. Numeration is the art numbering. It teaches to express the value of any proposed number by the following characters, or figures: 1, 2, 3, 4, 5, 6, 7, 8, 9, 0—or cypher. Besides the simple value of figures, each has a local value. which depends upon the place it stands in, viz. any figure in the place of units, represents only its simple value, or so many ones, but in the second place, or NOTE--Although a cypher standing alone signifies nothing; yet when it is placed on the right hand of figures, it increases their value in a tenfold proportion, by throwing them into higher places. Thus 2 with a cypher annexed to it, becomes 20, twenty, and with two cyphers, thus, 200, two hundred. Q. When numbers consisting of many figures, are given to be read, it will be found convenient to divide them into as many periods as we can, of six figures each, reckoning from the right hand towards the left, calling the first the period of uits, the second that of millions, the third billions, the fourth trillions, &c. as in the following number: 8 0 7 3 6 2 5 4 6 2 7 8 9 0 1 2 50 4. Period of 3. Period of 12. Period of Trillions. 8073 Billions. 625462 Millions. 789012 6 7 9 2 1. Period of 506792 The foregoing number is read thus-Eight thousand and seventy-three trillions; six hundred and twenty-five thou sand, four hundred and sixty-two billions; seven hundred and eighty-nine thousand and twelve millions; five hundred and six thousand, seven hundred and ninety-two. N. B. Billions is substitute 1 for millions of millions. Quatrillions for millions of milkens of millions of millions place of tens, it becomes so many tens, or ten times its simple value, and in the third place, or place of hundreds, it becomes an hundred times its simple value, and so on, as in the following To know the value of any number of figures. RULE. 1. Numerate from the right to the left hand, each figure in its proper place, by saying, units, tens, hundreds, &c. as in the Numeration Table. 2. To the simple value of each figure, join the name of its place, beginning at the left hand, and reading to the right. EXAMPLES. Read the following numbers. 365, Three hundred and sixty-five. 5461, Five thousand four hundred and sixty-one. 54096, Fifty-four thousand and twenty-six. 123461, One hundred and twenty-three thousand foar hundred and sixty-one. 4666240, Four millions, six hundred and sixty-six thousand two hundred and forty. NOTE. For convenience in reading large numbers, they may be divided into periods of three figures each, as follows: 987, Nine hundred and eighty-seven. 987 000, Nine hundred and eighty-seven thousand. 987 000 000, Nine hundred and eighty-seven million. 987 654 521, Nine hundred and eighty-seven million, six hundred and fifty-four thousand three hundred and twenty-one. To write numbers. RULE. Begin on the right hand, write units in the units place, tens in the tens, place, hundreds, in the hundreds place, and so on, towards the left hand, writing each figure according to its proper value in numeration; taking care to supply those places of the natural order with cyphers which are omitted in the question. EXAMPLES. Write down in proper figures the following numbers Thirty-six. Two hundred and seventwines Thirty-seven thousand, five hundred and fourteen. Nine millions, seventy-two thousand and two hundred. Eight hundred millions, forty-four thousand and fiftyfive. Is SIMPLE ADDITION, putting together several smaller numbers, of the same denomination, into one larger, equal to the whole or sum total; as 4 dollars and six dollars in one sum is 10 dollars. RULE. Having placed units under units, tens under tens, &c. draw a line underneath, and begin with the units; after adding up every figure in that column, consider how ma ny tens are contained in their sum; set down the remainder under the units, an carry so many as you have tens, to the next column of tens; proceed in the same manner through every column, or row, and set down the whole amount of the last row. |