OX AVERAGING ACCOUNTS. 775 



from this "basis" date we will have to pay the total amount of the bills 

 in order to consume all the interest, so that there would be interest nei- 

 ther owing to nor by us, by dividing the total interest due by the interest 

 on the whole for one day. 



9O9. On computing interest at 1 per cent, per Month or 12 per cent, 

 per Annum. We call a month thirty days ; therefore at this rate per 

 cent, the principal earns 1 per cent, every 30 days, and T V per cent, every 

 3 days ; consequently to find the interest for 30 days, we simply move the 

 decimal point between dollars and cents two places to the left, and for 

 3 days we move it three places to the left. With a very little practice, in- 

 terest may be very rapidly computed at this rate per cent. In the exam- 

 ple under 904-, we first find the interest for 30 days on $350, which is 

 0; for 60 days it is twice that amount, or $7.00; and for 3 days 

 35c. ; and 1 day, J of 35c., which is 12c, Then we add GO days, $7.00 ; 3 

 days. 35c. : 1 day 12 cents; total 64 days, $7.47. Then $2.00, 30 days ; 

 and for 3 days 20 cents. ; 9 days, three times 3 days, and consequently, 

 three times 20c., or GOc. Then we add 30 days, $2.00 ; 9 days, GOc. ; total 

 39 days, 2.60. Then if $1.40 for 30 days, for 90 days it is three times 

 that amount, or 4.20; and if 14 cents for 3 days, it is J of that amount 

 for 1 day, or 5c. ; total 91 days, S4.25. 



$290 for 3 days 29c. 



" 1 day, add \ of amount f jr 3 days, 10 



39o. 



$240 for 30 days, $2.40 



" 3 days24c ; for 1 day, \ of 24c 8 



$2 48 



$150 for 30 days, $1.50 ; for 15 days, of $1.50, or 7 

 " 3 days, 15c. ; for 1 day }of 15c., 6 



80 



$100 for 30 days, $1.00 ; for 90 days, $3.00 



:; days, 10c. ; for 2 days of 10c., 7 



H96 

 The foregoing illustration is d iilicirnt to nnk> perfectly clear 



to the mind the 1 percent. in-tli<l ,,f li^unn^ intcivst, ;iii<l when by con- 

 tinued practice t .u^ly mas ten 1, th-- oM torture 

 of a\ accounts is rendered, on the contrary, a, pleasure. 



