COMPUTE in COBOL is the best keyword you can use it in calculation. The syntax explained here simplified way you can use it. Read more.
Really the best COBOL tutorial help you go thorough quickly to write programs and prepare for interview.
The simple and effective answer for STOP RUN and how it works in various scenarios
The best way you can use Indexed file Read syntax in your project with less efforts. This is a way of writing good syntax in COBOL.