Leonardo Da Vinci’s mathematics teacher, Luca Pacioli who was also a Franciscan monk, is usually credited with creating the ‘double entry’ method of book-keeping. Whether that is correct, or whether it was Benedikt Kotruljevic who wrote about the subject in 1458 can be debated. But the approach used by today’s accounting organizations in this day and age was developed in the 15th century. However, most small business owners struggle with the double entry concept. It might be easy for accountants who have undertaken a lot of education, but folks who just want to get on and run a business do not have that opportunity.