Εικόνες σελίδας
PDF
Ηλεκτρ. έκδοση

HE

TEACHERS' ASSISTANT;

OR,

A SYSTEM OF PRACTICAL ARITIMETIC:

WHEREIN

THE SEVERAL RULES OF THAT USEFUL SCIENCE ARE

ILLUSTRATED BY A VARIETY OF EXAMPLES

A LARGE PROPORTION OF WHICH ARE IN

FEDERAL MONEY.

THE WHOLB DESIGNED

TO IBRIDGE THE LABOUR OF TEACHERS, AND TO

FACILITATE THE INSTRUCTION OF YOUTH.

& NEW EDITION, WITH CORRECTIONS AND ADDITIONS OF THE AUTHOR.

REVISED.

COMPILED BY STEPHEN PIKE.

PHILADELPHIA :
PUBLISHED BY M. POLOCK.

1852.

Karvard College Library

Nov. 22, 1921

Sosier fund
ENTERED according to Act of Congress, in the year 1838, by

M-CARTY & Davis,
is the Office of the Clerk of the District Court of the Eastern

District of Pennsylvania.

Signs.

+

of Xi

EXPLANATION OF CHARACTERS.

Significations.
equal; as 20.= L. 1.
more ; as 6+2=8.
less

;

as 8-2=6.
into, with, or multiplied by ; as, 6x2=12.
moby (i.e. divided by) as, 6+2=3; or, 2)6(3.

proportionality; as, 2 : 4 :: 6 : 12. ✓or y Square Root; as, %64=8.

3 Cube Root; as, /64=4.

Fourth Root; as, 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.

[ocr errors]
[ocr errors]

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 em-
ployed : viz. unit, ten, hundred, thousand, and mil-
lion; 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 thou-
sands, 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 num-
ber of units, or that number of tens, or that number of
hundreds, &c. a: cording to its relative place : which
exemplified in the following tables.

B

« ΠροηγούμενηΣυνέχεια »