The following will be found convenient in the absence of extended interest tables.

To find the interest on a given sum, for any number of days, at any rate of interest.

At five per cent., multiply the principal by the

number of days, and divide by ......................

72

At 6 per cent., as above , and divide by ..................

.60

At 7 per cent., as above , and divide by ..................

52

At 8 per cent., as above , and divide by ..................

45

At 9 per cent., as above, and divide by.....

40

At 10 per cent., as above , and divide by ..................

36

At 12 per cent., as above , and divide by ..................

30

At 15 per cent., as above, and divide by.....

24

At 20 per cent., as above , and divide by ..................

18