As a supplemental or stand-alone text, Essentials of Flowcharting covers the basics of flowcharting and pseudocode as related to structured programming. It can be used in many courses such as general programming, COBOL, Pascal, BASIC, and FORTRAN. For the instructor who believes their students benefit from visualizing the flow of a program, Essentials of Flowcharting is a perfect solution.
Someone wiser than us has decided that one should learn how to calculate manually before giving them a calculator. Supposedly this way they have an idea of what goes on in that little black box. Personally, I am not interested n how it gets there.
Following this logic, one should know the "Essentials of Flowcharting" before buying ABC Flowchart or its equivalent. Measure twice and cut once. This has lots of practical examples, unlike those toy charts you make at school.