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2202                                                              ARITHMETIC

$600, or the sum of money named in the note, is called the face of the note.

Notes should state value received, the date, face, rate, person to whom payable, and time of payment.

John A. Briggs is the payee, or the one to whom the money is to be paid.

George H. Brown is the maker, or the one who signs the note. Find the interest on $600 at 5% for 3 years. $600 .05 30.00 interest for 1 year at 5%

___3

90.00 interest for 3 years at 5%

To find the interest, we multiply the principal by the rate for 1 year, and the product by the number expressing the time in years.

EXERCISE 39. Find the interest on

1.   $1250 for 4 yr. at 6%

2.   $ 875 for 5 yr. at 5%

3.   $275.50 for 2 yr. at 41%

4.   $1620 for 8 yr. at 44%

5.   $9750 for 3 yr. at 4%

6.   $2250 for 7 yr. at 5%

7.   $ 750 for 3 yr. at 3.5%

8.   $1500 for 4 yr. at 47%

There are many methods of computing interest.

The following method is a most practical one. It is accurate, and it does much to develop a child's mathematical resources, inasmuch as it gives him power and skill in thinking out fractional parts.

Rule for interest. Multiply the principal by the rate per cent for 1 year. Draw a line to separate this result from the work below. Take such multiples or parts of the product as will give the interest for the required time.

Find the interest on $1250 for 3 yr. 5 mo. 10 da. at 6%. $   1250

_____.06

$  75.00 = interest for 1 yr. at 6%

$225.      = interest for 3 yr. at 6%

$ 25.     = interest for 4 mo. at 6%

$   6.25   —interest for 1 mo. at 6%

$  2.083 = interest for 10 da. at 6%

$258.333 = interest for 3 yr. 5 mo. 10 da. at 6%

We first find interest for 1 yr., $75. Draw the line under it, as it is the fundamental part of the work—the part to which we constantly refer. The interest for 3 yr. = 3 times that of 1 yr. 3 X $75. == $225.

9.   $ 900 for 21 yr. at 7%

10.   $4150 for 31 yr. at 41%

11.   $2350 for 3 yr. 6 mo. at 4%.

12.   $8775 for 2 yr. 3 mo. at 51%

13.   $ 375 for 4 yr. 4 mo. at 6%

14.   $ 500 for 5 yr. 2 mo. at 3.5%

15.   $1200 for 4 yr. 6 mo. at 4.2%