Working with Excel Data
Move beyond basic cell entries and static sums to build reliable, adaptable spreadsheets. Learn how to combine dynamic lookup formulas, clean irregular inputs, summarize multi-dimensional tables, and troubleshoot complex calculation models.
Like Duolingo, but for Working with Excel Data. Tomo turns the whole topic into a game you play five minutes a day, until it actually sticks.
27 levels across 4 sections, about 54 minutes end to end, roughly 11 days at five minutes a day. It moves through Unlocking Dynamic Formulas and Logic, Structuring and Safeguarding Raw Datasets, Summarizing and Highlighting Information, and Dynamic Calculations and Model Auditing. It assumes you already know the basics.
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Key ideas in Working with Excel Data
- VLOOKUP uses a hardcoded integer index that cannot adapt when columns shift.
- XLOOKUP references explicit cell ranges that Excel automatically adjusts on column insertion.
- XLOOKUP includes a built-in [if_not_found] argument as its optional fourth parameter.
- Using XLOOKUP's native argument prevents masking real syntax errors that IFERROR hides.
- Exact match finds identical values without requiring the search column to be sorted.
- Approximate match scans stepped numeric bins and requires strictly ordered thresholds to return correct tiers.
- XLOOKUP match modes -1 and 1 evaluate nearest smaller or larger items across sorted data.
- The inner XLOOKUP finds the column header and returns a single vertical slice of the grid.
- The outer XLOOKUP searches that dynamic returned column slice for the target row value.
- VLOOKUP cannot search a column and retrieve values located to its left.
- XLOOKUP decouples the search vector from the return vector, allowing leftward lookups natively.
- INDEX/MATCH separates lookup and retrieval into distinct coordinates, enabling leftward lookups.
- In SUMIFS, every criteria range must match the exact row and column dimensions of the sum range.
- Mismatched range sizes across SUMIFS arguments trigger an immediate #VALUE! calculation error in Excel.
- Aligning the start and end row boundaries across all ranges resolves the dimension conflict.
- Excel criteria arguments require logical comparison operators to be enclosed within text quotes.
You've tried the other tabs
Thirty open tabs. Four facts you actually kept.
You watched. You nodded. By Sunday it was gone.
One answer, then back to scrolling.
Eight weeks. You meant to finish. You didn't.
Tomo gives Working with Excel Data the Duolingo treatment: levels, streaks, and quick quizzes that test what you just learned. That game loop is what the tabs above never had, so it's the one you actually finish.
Here's what playing it feels like
A real question from this course. Take your best guess.
Why does XLOOKUP continue pulling the right data after you insert a new column?
Get it right to open this lesson and 26 more in the app.
Where Working with Excel Data takes you
- 1
Unlocking Dynamic Formulas and Logic
- Connecting Tables with Modern Lookups
- Multi-Criteria Counting and Aggregation
- 2
Structuring and Safeguarding Raw Datasets
- Dynamic Tables and Structured References
- Text Transformation and Data Hygiene
- Defensive Sheet Design and Input Controls
- 3
Summarizing and Highlighting Information
- PivotTables for Multi-Dimensional Summaries
- Visual Hierarchy with Conditional Formatting
- 4
Dynamic Calculations and Model Auditing
- Dynamic Arrays and Spilling Logic
- Formula Auditing and Error Diagnostics
4 sections · 9 units · 27 levels. Built to play, not to enroll.
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Tomo is also a ChatGPT plugin: the same playable courses, built and played inside your chat.
Add Tomo to ChatGPT- What to ask
- “Make me a Tomo course on black holes.” “Turn this chat into a Tomo course.”
- What you get
- Quick questions with instant feedback, hearts and stars, ready to play in about a minute.
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- No sign-up to start. Connect your Tomo account and your streak carries on in the app.
You pick the voice
Working with Excel Data is taught in the Professor style: clear, structured, thorough. Want a different feel? In the app you can spin up the same topic in any of Tomo's teaching styles. Same facts, totally different vibe.
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Start Working with Excel Data today.
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