Real situations from working spreadsheets — sales targets, commission tiers, messy exports, aged invoices. Numbered in recommended order: start at 1 and work down, or filter to what you need.
5 exercises — Data Cleaning
Clean inconsistent spacing and casing so values can be matched.
Find rows whose order number appears more than once in the column.
COUNTIF · IF
Use COUNTIF to reconcile two lists and spot what is absent.
COUNTIF · IF
Match two lists where one side has trailing spaces you cannot see.
COUNTIF · IF
Diagnose a match failure where both values look identical on screen.
XLOOKUP
| # | Exercise | Functions | Difficulty | Time | Status |
|---|---|---|---|---|---|
| 41 | Standardise messy codes with TRIM and UPPERHarbor Supply — supplier feed, uncleaned | — | Intermediate | 7 min | 25 pts |
| 48 | Spot duplicate order numbers with COUNTIFHarbor Supply — order import, run twice | COUNTIF · IF | Intermediate | 9 min | 30 pts |
| 78 | Find which customers are missing from a listHarbor Supply — CRM customers versus billing records | COUNTIF · IF | Advanced | 14 min | 40 pts |
| 82 | Reconcile a list with hidden spacesHarbor Supply — export vs master customer list | COUNTIF · IF | Advanced | 12 min | 35 pts |
| 84 | Why does a lookup fail on clean data?Conceptual question — no dataset | XLOOKUP | Advanced | 4 min | 30 pts |