The method of reckoning interest generally used by the best accountants and book-keepers is what is known as the sixty-day method. By this method 360 days are rec-oned as a year and 30 days as a month. Six 101 per cent, for 12 months, or 1 year, is equivalent to 1 per cent. for 2 months, or 60 days, and 1 per cent. of any number is easily found by moving the decimal point two places to the left. Therefore, the interest on any amount at 6 per cent. per annum for 2 months, or 60 days, may be found by moving the decimal point two places to the left. Having found the interest for 60 days, in order to find it from that amount for any number of days, simply divide them into aliquot parts of 60.
Example i : Interest on $128 for 90 days.
1.28 = interest for 60 days. .64= interest for 30 days.
1.92 = interest for 90 days. 60+30.
Example 2 : Interest on $185.40 for 47 lays.
1.8540 = interest for 60 days.
.9270 = interest for 30 days, 1/2 of 60. 4635 = interest for 15 days, 1/2 of 30. .0618 = interest for 2 days, 1/15 of 30.
1.4523 == interest for 47 days. 30+15+2. Interest Table.
The interest on any sum of money may readily be found by means of the following table showing the interest on $1 at various rates and times:
Find interest for $1 in this table at given per cent, for given number of years, months and days and multiply by the given amount.