HE TEACHERS' ASSISTANT; OR, A SYSTEM OF PRACTICAL ARITHMETIC: WHEREIN THE SEVERAL RULES OF THAT USEFUL SCIENCE ARE A LARGE PROPORTION OF WHICH ARE IN FEDERAL MONEY. THE WHOLE DESIGNED TO BRIDGE THE LABOUR OF TEACHERS, AND TO & NEW EDITION, WITH CORRECTIONS AND ADDITIONS BY THE AUTHOR. REVISED. COMPILED BY STEPHEN PIKE. PHILADELPHIA: PUBLISHED BY M. POLOCK. Harvard College Library Nov. 22, 1921 So ier fund ENTERED according to Act of Congress, in the year 1838, by in the Office of the Clerk of the District Court of the Eastern Signs. :::: EXPLANATION OF CHARACTERS. Significations. equal; as 20s.-L. 1. more; as 6+2=8. less; as 8-2=6. into, with, or multiplied by; as, 6×2=12. by (i. e. divided by) as, 6÷2=3; or, 2)6(3. proportionality; as, 2 : 4 :: 6 : 12. ✔or Square Root; as, Cube Root; as, Fourth Root; as, 64-8. 64-4. 16-2, &c. A Vinculum; denoting the several quantities over which it is drawn, to be considered jointly as a simple quantity ARITHMETIC. ARITHMETIC is the art of computing by numbers. It has five principal rules for its operations; viz. numeration, addition, subtraction, multiplication, and division. NUMERATION. Numeration teaches to write or express numbers by figures, and to read numbers thus written or expressed. In treating of numbers, the following terms are employed: viz. unit, ten, hundred, thousand, and million; as also billion, trillion, and some others. But the latter are seldom used. A unit is a single one. A ten is ten units. A hundred is ten tens. A thousand is ten hundreds. A million is ten hundred thousands. Note.—As it takes ten hundred thousands to make a million, when we express a number greater than a thousand, and less than a million, we use tens of thousands, or hundreds of thousands, or both, as the case requires. Likewise, to express a number greater than a million, we employ tens of millions, or hundreds of millions, &c. The following are the figures used in numeration. with their names above them. One two three four five six seven eight nine 1 2 3 4 5 6 7 8 9 Each of these figures represents the number which its name denotes; but it is understood to be that number of units, or that number of tens, or that number of hundreds, &c. a cording to its relative place: which is exemplified in the following tables. |