The short answer
Leading zeros may be part of IDs; blanks are not zero; names can hide different variants. Work on a copy with a change log.
Try it in three steps
- Label ID, quantity and amount columns.
- Define conversions and missing-value rules.
- Compare row counts and key totals before and after.
A practice prompt
Before you start
Practice cleaning rules before comparing stock tables.
Practice material (fictional)
ID 001 has blank quantity; 002 has quantity 0; 003 contains text 8 boxes.Replace placeholders in the prompt with this material, or append the material if there are no placeholders. Reading time excludes doing the exercise.
Suggest cleaning rules without editing: preserve leading zeros, leave unknown quantities unknown and keep variants separate.What to look for (not a recorded test result)
Preserve leading zeros, distinguish blank from zero, and document splitting 8 boxes into quantity 8 and unit boxes.
If it goes wrong
If totals change, inspect missing rows, units and duplicate rules before accepting the result.
Check your result
Changes follow explicit rules and the original remains recoverable.
References and scope
The links below support the concepts or product navigation. The steps and exercises are our teaching suggestions, not official certification or measured customer outcomes. Product interfaces and availability may change. References checked on 2026-10-17.