The practice is that which fhews the method of working by numbers, and confequently becomes the most useful and expeditious for bufinefs, and has five principal or fundamental rules for the operation, viz.

1. Numeration, or Notation; 2. Addition; 3. Subtraction; 4 Multiplication; and 5. Divifion.

SECT. I.

NUMERATION.

to write

EACHETH to read or exprefs the true value of any number any propofed number according to its true value; and this confisteth of two parts.

1. The true order of placing down figures.

2. The true valuing of each figure in its place; both of which are plainly exhibited in the following

In this table each figure from the place of units, increafeth in a ten

fold proportion; as 9 in the firft place is nine; 9 in the second place is ninety; and fo of the reft.

These ten places are as far as any common business will require; but when large numbers are expreffed by figures, for the more eafy reading of them, divide, or rather diftinguish your number into periods, each period to contain fix characters or figures, called grand periods; then the firft period to the right hand will be units, the fecond millions, third billions, fourth trillions, fifth quadrillions, fixth quintillions, feventh fextillions, eighth feptillions, ninth octillions; tenth nonillions, eleventh deci-millions, &c. As for inftance, suppose I would number this train of figures, viz.

Septill,

3

Septill. Sextill. Quint. Quadr. Trill. Billions. Millions. Units.

8

7

6

4

3

2

I

5 123456,124121,681213,415682,181643,214168,218164,823812. EXAMPLES.

Write down 34167 in words at length? Anfwer, Thirty-four thoufand, one hundred and fixty-feven.

Write down 790684218 in words at length? Anfwer, Seven hundred ninety millions, fix hundred eighty-four thoufand, two hundred and eighteen.

Exprefs in figures, fix thousand and fifty-five? Answer 6055.

Exprefs in figures, nine hundred eighty-feven millions, fix hundred and fifty thousand? Answer 987650000.

Exprefs in figures, feventeen millions, feventeen thousand, feventeen hundred and feventeen ?

17000000

17999

1700

17

17018717 Answer.

Exprefs in figures, forty-five billions, four hundred, forty-five thousand and four millions, fixty thoufand, fix hundred and fifteen ? Anfwer 45445004060615.

NOTATION, by Roman Numerical Letters.

One, five, ten, fifty, hundred, five hundred, thousand.

D.

M.

1. V. X. L. C. When a lefs numerical letter ftands before a greater, it must be taken from it, as I before V or X, and X before L or C, &c. thus:

Four, nine, forty, ninety, &c.

IV. IX. XL. XC.

When a less numerical letter ftands after a greater, it is to be added to it, thus:

Six, eleven, fixty, one hundred and ten.
VI. XI. LX.
CX.

A line drawn over any number less than a thousand, fignifies so many thousands, as XL. is forty thoufand; C, is one hundred thousand; M. is one million, &c.

Write down in common figures the following numbers, expreffed in numerical letters, viz.

XI. C. DC. DXL. MC.

Anf. 11, 100, 600,

540, 1100

MDCCLXXXI. MC.
1781, I 100000.

Write down in numerical letters the following number, expreffed in common figures, viz.

19, 50, 95, 101, 1000, 1500, 60000. Anfwer, XIX. L. XCV. CI.

M MD. VI.

Write down in numerical letters the following numbers expreffed in common figures, viz. 2060000. Anfw. MMLX.

B 2

II. ADDI

TEA

EACHETH to add fundry numbers together, into one fum, called the total.

RULE. 1. Place all the numbers of a like name fo, that units may ftand under units, tens under tens, hundreds under hundreds, &c.

2. Begin at the units place, and reckon up all the figures in that place from the bottom to the top, and what overplus there is above even tens, fet down, carrying one for every ten to the next row, and fo on, continuing to the laft row, at which fet down the total amount. PROOF. Begin at the top of the fum, and reckon the figures downwards, in the fame manner as you added them upwards; and if the fum comes the fame as before, it is undoubtedly fuppofed to be right. EXAMPLES.

Let these numbers be added together:

9482

590

307

85

10464

fay the fum of 5 and 7 is 12, and
The fum of 1 and 8 is 9, and 9
Then 2 and 3 is 5, and
Lastly, I and 9 is 10,

To add up this fum, begin at 5, 2 is 14; fet down 4 and carry 1. is 18, and 8 is 26; fet down 6 and carry 2. 5 is 10, and 4 is 14; fet down 4 and carry 1. which being the laft, fet it down.

More examples for practice.

126893

12486

368121

21304
2186

Questions to exercife Addition of Whole Numbers.

Queft. 1. A Gentleman had in his nursery one hundred million of oak, one hundred thousand ash, and one hundred fruit trees,and alfo fixty-nine elm trees; I demand how many trees were growing in the nusery?

Queft. 2. A perfon was born in year 1800, when will he (if he lives) be 65 years of age?

This is no more then to

Add

1800

65

Anfwer 100100169 Trees in all. And we have the year required 1865

Queft. 5. A draper has 7 pieces of cloth as under.

Yards

Queft. 6. How is eleven thousand, eleven hundred, and eleven set down in 5 figures? 12111. Anfwer.

Proof.

1 1000

I 100

II

12111

Quest. 7. In the fecond book of Kings Chap. 19th we read that an angel deftroyed in the camp of the Affyrians, an hundred, and fourscore, and five thousand: How would you fet this down? 185000. Answer.

PARADOXICAL QUESTIONS.

Queft. 1. If from fix ye take nine and from nine ye take ten,
(Ye wits, now the myft'ry explain)
And if fifty from forty be taken; there then
Shall be just half-a-dozen remain.

SOLUTION.

I

If from SIX you take nine = IX, there then remains S
And if from IX you take ten = X, there remains
And if from XL you take fifty = L, there remains X

Queft. z.

Four things I faw, but what they were,
I beg, dear ladies, you'll declare;
And though they were but four exa&,
Thirteen they were full as compact;
I cut off half, and then could find,
Exactly eight were left behind:
What feems more ftrange, tho' very fure,
Thefe eight remaining, were but four.

SOLUTION. Divide thirteen by line that's ftrait,
The balf is evidently eight.

Queft. 3.

}

}

= SIX.

XIII

Three perfons at play, in a tavern were feated,
Where none other play'd, nor any one betted;
Yet fortune prov'd kind, for each gain'd a guinea,
Who tells me this paradox, I hold him no ninney.

Anfwer Three Muficians

Find how many Years it was from the Creation of Adam to the univerfal Deluge in the Days of Noah, called Noah's Flood; by the 5th Chapter, and 6th Verse of the 7th Chapter of Genefis.