In Roasting Old Chestnuts 3 ,I promised a final look back on school days and some of the mathematics attempted by many school children in preparation for their 'O' level (GCSE).
If Durell was not the arithmetic book that regularly journeyed between home and school then Hall and Stevens could well have been the book you used for this aspect of your mathematical development. Five hundred and odd pages of close type with very few diagrams, the assumption about your level of comprehension and general knowledge was high.
Profit and loss was a rich source of questioning:
[In those days there were 12 pennies(d) to a shilling(s) and 20 shillings to the pound!]
[It is not 12 1 / 2 !]
Perhaps more in keeping with present times the questions concerned with simple or compound interest and discount would still have some relevance?
Perhaps knowing that:
present value + interest on the present value = sum due
interest on the present value = discount on sum due
will help you with:
Finally while in this fiscal vein:
The previous articles in the series were Roasting Old Chestnuts , More Old Chestnuts and Roasting Old Chesnuts III .