Having placed the principles of accountancy in a small separate volume, we are enabled to prepare, by the unit plan, practice sets that severally afiord a business routine which will directly familiarize the student with the commodities, processes, and trade conditions prevail ing in any one of the hundred or more classified lines of business or organized interests. These units are graded, and can be selected from The American Bookkeeping Series, for which this book is the reference in account ancy matters.