Excel is a grid of cells, each with an address. Everything you will learn later — functions, lookups, pivot tables — rests on one thing: is your data laid out in a way the program understands?
1 The vocabulary you need
=B2*0.15
Cell C2 displays 1,500, but the formula bar reveals it is the result of =B2*0.15 — and that difference is the first thing to check in any file.
| Term | What it is | Example |
|---|---|---|
| Workbook | The file itself | trial-balance-2026.xlsx |
| Worksheet | A page inside the file | January · February · Summary |
| Cell | The intersection of a column and a row | B4 |
| Reference | The address of a cell or a range | B4 · B4:B20 |
| Formula bar | Shows what was actually typed into the cell | =B4*0.15 |
The cell shows a result; the formula bar shows the truth
You may see 1,500 in a cell when it is in fact a formula, a piece of text, or a value typed in by hand. Before you trust a number in any file, click its cell and look at the formula bar.
2 The four data types
| A | B | C | |
|---|---|---|---|
| 1 | Item | Value | Type |
| 2 | Sales | 250000 | Number |
| 3 | Date | 2026-01-31 | Date (a number underneath) |
| 4 | Customer | Al Waha Company | Text |
| 5 | Approved? | TRUE | Logical |
| 6 | Tax | =B2*0.15 | Formula |
Numbers stored as text: enemy number one
If you see numbers aligned to the left, or a small green triangle in the corner of the cell, they are text rather than numbers — and SUM will ignore them and hand you a zero without complaint. This happens constantly with data exported from accounting systems.
3 The rules for a sound table
One header row
No merged or doubled headers
One record per row
A single transaction, no more
One field per column
And never mix two types in one column
No blank rows
A gap breaks the range
No merged cells
They ruin sorting and filtering
Raw data kept separate
One sheet for data, another for the report
Six rules that save you hours of fixing files later
The bad one: a single column called “Amount” holding “SAR 1,200”, “one thousand two hundred” and “1200”, a merged row above the headers, and two blank rows in the middle to separate the months.
The sound one: separate columns — Date · Entry number · Account · Cost centre · Debit · Credit — one entry per row, with January and February in the same table and a “Month” column distinguishing them.
The result: the sound table becomes a pivot report in three clicks; the bad one has to be re-entered.
4 Shortcuts worth memorising
Always start with Ctrl + T
Turning your data into a “Table” gives it a name, expands the range automatically when you add rows, and lets your formulas read [@Amount] instead of D2. That single habit prevents most “the range didn’t include the new rows” errors.
Lesson summary
- A workbook is a file, a worksheet is a page, a cell is an address — and the reference is Excel’s language.
- The cell shows a result; the formula bar shows what was actually typed.
- Numbers stored as text break your sums silently.
- One header row, one record per row, no gaps and no merging.
- Keep the raw data separate from the report sheet.
5 Test your understanding
Three quick questions
Pick the answer you believe is correct and you will see the result immediately.
1. A column contains numbers but its total shows zero. The most likely cause:
The tell-tale signs: left alignment and a green triangle. The fix: convert the column to numbers before summing.
2. Why do we avoid merged cells in a data table?
Merging is for final presentation only. A data table must stay a regular grid.
3. What is the benefit of converting a range into a Table with Ctrl + T?
A Table makes formulas, pivots and charts follow your data when new rows are added.