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Place 5 opposite 1: now 1 is opposite 2=1, the

answer.

TO MULTIPLY ONE FRACTION BY ANOTHER.

Rule.-Reduce one to decimals: then place the numerator of the other opposite the denominator : then opposite the decimal is the answer in decimals, which, if desired, can be reduced to a vulgar fraction by the preceding rules.

TO REDUCE THE DIFFERENT CURRENCIES TO FEDERAL

MONEY.

Rule.- Place the 1 on the circular, opposite the number of shillings and parts of a shilling composing a dollar of the currency to be reduced: then, opposite the given number of shillings is the answer.

Example.--Reduce 5 shillings, New York currency, to Federal money.

Place 1 (on the circular) opposite 8: then opposite 5 shillings, is .625, the answer.

In 15 shillings, how much?
Opposite 15 is 1.875, the answer.
In 32 shillings, English currency, how much?

Place 1 (on the circular) opposite 4:5: then opposite 32, is $7.11, the answer.

In 9 shillings, how much ?
Opposite 9 is $2, the answer.

INTEREST.

TO COMPUTE INTEREST FOR YEARS.

RULE.Place the rate per cent. found on the cir cular, opposite 1: then opposite the principal is the interest.

Example. What is the interest of $50 at 7 per cent. ?

Place 7 opposite 1: then opposite 50 is $3-50, the

answer.

What is the interest on $40 at 64 per cent. ?

Place 6.5 opposite 1: then opposite 40 is $2.60, the answer.

TO COMPUTE INTEREST FOR MONTHS. RULE.—Place the principal, (found on the circular,) opposite the gauge point for months at the given per cent. : then opposite the given number of months is the answer. Example.

What is the interest on $50 for three months at 7 per cent. ?

Place 50, (found on the circular,) opposite 1714, (the gauge point for months at 7 per cent.,) then opposite 3 months is •875, the answer.

What is the interest on $60. for eight months at

6 per cent ?

Place 60 opposite -2, (the gauge point for months at 6 per cent.,) then opposite 8 months is $2:40, the

answer.

TO COMPUTE INTEREST FOR DAYS.

Rule.-Place the principal, (found on the circular,) opposite the gauge point for days at the given per cent.: then opposite the number of days is the answer.

Example.- What is the interest on $55 for 15 days at 6 per cent?

Place 55 opposite 600, (the gauge point for days at 6 per cent.,) then opposite 15 days is .13 3-4.

The PRINCIPAL AND INTEREST BEING GIVEN, TO FIND

THE RATE PER CENT.

RULE FOR ONE YEAR.—Place the interest opposite the principal : then opposite 1 is the rate per cent.

Example.-Received $7.00 for the use of $50.00 for one year; what was the rate per cent. ?

Place 7 opposite 50 : then opposite 1 is 14, the answer, 14 per cent.

Gave $4:00 for the use of $80.00 one year: whatwas the rate per cent. ?

Place 4 opposite 80: then opposite 1 is 5, the answer, 5 per cent.

RULE FOR MONTHS.--Place the given interest opposite the given number of months: then observe the number opposite 12. Now place this number opposite the principal: then opposite 1 is the rate per cent.

Example.—Paid 25 cents for the use of $5.00 for 4 months : what was the rate per cent. ?

Place 25 opposite 4: then opposite 12 is 75. Now place 75 opposite $5.00: then opposite 1 is 15, (15 per cent.,) the answer.

Gave 14 cents for the use of $60.00 one month : what was the per cent. ?

Place 14 opposite 1: then opposite 12 is 1.68Now place 1.68 opposite 60: then opposite 1 is 2:8, (2% per cent.,) the answer.

RULE FOR DAYS.—Place the given interest opposite the given number of days: then observe the interest opposite 365 (the number of days in a year). Place this opposite the principal: then opposite 1 is the rate per cent.

Example.-Paid 14 cents for the use of $64.00 29 days: what was the rate per cent. ?

Place 14 opposite 29: now opposite 365 is $1.76. Now place 1.76 opposite 64: then opposite 1 is 2.75, (27 per cent.,) the answer.

Paid 23 cents for the use of $50.00, 21 days: what was the rate per cent. ?

Place 23 opposite 21: now opposite 365 is 4. Place 4 opposite 50: then opposite 1 is 8 per cent., the answer

THE RATE PER CENT. AND THE INTEREST BEING

GIVEN, TO FIND THE PRINCIPAL.

RULE FOR ONE YEAR.–Place the per cent. opposite 1: then opposite the interest is the principal.

Example.--At 7 per cent. I paid $3.50 for the use of money 1 year: what was the principal ?

Place 7 opposite 1: then opposite 3.50 is $50.00, the answer.

RULE FOR MONTHS.- Place the interest opposite the given number of months: then opposite the point of the given per cent., for months, is the answer.

Example.- Gave $2.00 at 7 per cent. for three months: what was the principal ?

Place 2 opposite 3: then opposite 1.714 is $114:30, the answer.

RULE FOR DAYS.- Place the given interest opposite the given number of days: then opposite the gauge point for days stands the principal.

Example.- At 7 per cent., gave 15 cents for 20 days: what was the principal ?

Place 15 opposite 20: then opposite 521 (the gauge point for days at 17 per cent.) is $39.00, the

answer.

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