Calculator tapes preserve the math trail behind a workpaper number. Instead of showing only the final amount, they show the entries, subtotals, notes, and total that support the conclusion on the page.
That context helps reviewers follow the calculation without sending preparers back to a separate spreadsheet, calculator, or handwritten note. When the explanation is visible in the PDF, review comments can focus on the work instead of asking where the support lives.
Clear calculator tapes also make accounting workpapers easier to support later. They reduce back-and-forth during review and give preparers a cleaner way to explain how a total was reached.