If there is a NumberOfClasses field, sort by that field.
Create a Sub-summary when sorted by NumberOfClasses part on the layout.
Put a Text Line in the Sub-summary part "Number of Classes - <<NumberOfClasses>>"
This will produce the Text Number of Classes - 1" etc
Click on the Summary Part label, color it and it will color the entire Summary Part.
<< >> marks are a Merge Field and will contain whatever is in the field within the marks.
The report can be viewed in Preview Mode or on paper, not in Layout or Browse Mode.
I am in process of building my report letters using this approach by trial & error. When I create a New Layout, I choose the Report & sub-category form. I go thru the steps of selecting the fields I want to use, tne field I want to sort, the title on page, etc., then Finish. I then work on the positioning & arrangment of that page, but if I want to modify what i selected in building this layout, e.g., add fields, add/change sort fields, I have to start over with a new Layout. Is there a way to change the initial selections or is a new layout the only way?