- πΊπΈUnited States mark_fullmer Tucson
Reviewing the design of this module, I would recommend an alternate resolution: change the label of the "Number of pages" field to "Pages" and indicate in field help text that this can be entered as either a single page number (22) or a page range (22-25). The module is designed to pass that field value to the processors and render it correctly to show the page range.
This would seem to be preferable over math logic such as "[Start Page] + [Number of Pages] - 1".