ready reckoner for discounts, mid 19th century

Wages tables, 1850-1855
Ready reckoner giving the value of discounts of 10%, 15% and 20% on quantities between 15 and 36. This was probably a one-off instrument for use in a particular shop or workshop.
 
Currently on display in:
Mathematics
Year made :
mid 19th century
Inventory number :
1993-1243