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Explanation of Characters used in this Books
s Equal to, as 12d. = 18. signifies that 12 pence are
equal to 1 shilling.
+ More, the sign of Addition, as 5+7=12, signifies that
5 and 7 added together, are equal to 12.
Minus, or less, the sign of Subti action, as 6254, signifies that 2 subtracted from 6, leaves 4. x Multiply, or with, the sign of Multiplication ; as
4X3=12, signifies that 4 multiplied by 3, is equal to 12.
jo The sign of Division ; as 8:2=4, signifies that & di
vided 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: 4 ::8:16 ; that is, as 2 to 4, so 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 qumber is required. Denotes the biquadrate root, or fourth power, &c.
ARITHMETIC is the art of computing by numbers, , and has five principal rules for its operation, viz Numeration, Addition, Subtraction, Multiplication, and Division.
Numeration is the art of numbering. It teaches to ex. press 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 s• many ones, but in the second place, or
Note.- Although a cypher standing alone signißes nothing; yet when it is p! -d on the right hand of figures, it increases their value in a tenfold proportion, by thrı wing them into higher places. Thus 2 with a cypher annexed to it, becoines 20, twenty, and with two cyphers, thus, 200, two hundred.
2. 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 lefi, cal. ling the first the period of units, the second that of millions, the third billions, the furth trillions, &c. as in the following number: 8 0 7 3 0 2 5 4 6 2 7
6 7 9 2 4. Period of 3. Period of 12. Period of Period of Trillions. Billions. Millions.
8 9 0 1
506792 The foregoing number is read thus-Eight thousand and seventy three trillions ; six hundred and twenty-five thousand, four hundred and sixty. two billions ; seven hundred and eighty-nine thousand and twelve millions ; five hundred and sis thousand seven hundreu bod ninety-two.
N. B. Billions is substituted for 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
3 2 1 Three hundred twenty-one.
5 4 3 2 1 ..Fifty-four thousand 321. • 6 5 4 3 2 1 654 thousand 321.
7 6 5 4 3 2 1 7 million 654 thousand 821. 8 7 6 5 4 3 2 1 87 million 654 thousand 321. 9 8 7 6 5 4 3 2 1 - 987 million 654 thousand 321. 1 2 3 4 5 6 7 8 9 123 million 456 thousand 789. 9 8 6 5 4 3 4 8 - 987 million 654 thousand 348.
To know the value of any number of figures.
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.
Read the following numbers.
1234, One thousand two hundred and thirty-four, 54026, Fifty-four thousand and twenty-six.
123461, One hundred and twenty three thousand four
hundred and 'xty-one. 4666240, Four millions, six hundred and sixty-six thou
sana two hundred and forty. Note.--For convenience in reading large numbers, they may be divided into periods of three figur s 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 mo'lion. 987 654 321, Nine hundred and eighty-seven million, six
hundred and fifty-four thousand, three hun dred and twenty-one.
To write numbers.
Begin on the right hand, write units in the units place, tens in the tens place, hundreds in the hundreds $lace, 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.
Write down in proper figures the following rumbers :
Eight hundred millions, froty-four thousand and tiftyfive.
SIMPLE ADDITION, IS
S putting together several smaller numbers, of the same denomination, into one larger, equal to the whole or sum tolindas 4 dollars and six doliars in one sum is 10 dollars.
Having placed units 'inder uuts, tens under tents, &c. draw a line underneath, and begin with the units ; after adding up every figure in that cohumti, consiger how many tens are contained in their sum ; set down the remainder under the units, and carry so many as you have tens, to the next column of tens ; proceed in the same manner through every column, or w, and set down the whole amount of the last row.