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Intermediate Excel · Interactive lesson 10 of 12

Data cleanup & import basics

Data rarely arrives ready to use. Flash Fill, Text to Columns, and Remove Duplicates handle the most common messes in seconds — and a quick check after any import confirms Excel is actually treating your numbers as numbers.

IntermediateInteractive

Screens shown: Excel for Microsoft 365 for Windows. Practice works in any browser.

Written tutorialImporting and Cleaning Data in Excel

Skill check

Try these first:

  • Use Flash Fill to extract a pattern from one column into another.
  • Split one column into several with Text to Columns.
  • Remove exact duplicate rows.
  • Check whether a numeric-looking column is actually stored as text.

All familiar? Skip ahead to I11 — Workbook Organization.

Targeted teach

What you're learning

Flash Fill
Type the result you want for the first row by hand — Excel spots the pattern and offers to fill the rest of the column instantly.
Text to Columns
Splits one cell's content into several columns using a delimiter — comma, space, or another character.
Remove Duplicates
Deletes rows that repeat exactly, keeping the first occurrence.
Find and Replace
Ctrl+H — swaps every occurrence of one value for another in one pass, useful for standardizing an abbreviation.
Basic CSV import
A comma-separated text file opens straight into columns — the comma is what tells Excel where one field ends and the next begins.
Checking data types
A number stored as text lines up left instead of right, and functions like SUM quietly skip it — worth checking right after every import.

Where to find it in Excel

Data›Get & Transform · Data Tools

Swipe sideways to see the whole window.

  1. 1From Text/CSV imports a file and lets you check each column's data type first.
  2. 2Text to Columns splits one column into several.
  3. 3Flash Fill (Ctrl+E) copies the pattern you typed in C2 down the column.
  4. 4Remove Duplicates drops repeated rows (row 5).

Rendered view of Excel for Microsoft 365 (Windows). Ribbon layout can differ slightly on Mac, Excel for the web or a narrow window.

Guided practice

A messy customer export. Run each tool below on it, in order.

🧹 Customer Import — unedited
Start with "Flash Fill first names" — the pattern comes from the first row's already-filled example.
Name,State,Phone
Rosa Alvarez,Calif.,555-0142
Grant Okafor,NY,555-0198

Independent variation

Clean a real export

Take a genuinely messy list — a CSV export, a copy-pasted sign-up sheet — and run it through Flash Fill, Text to Columns, Find and Replace, and Remove Duplicates as needed. Finish by confirming every numeric column is actually stored as a number, not text.

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