Excel · Basics

Excel from zero: grid, ranges, and your first formula

Lesson 1 starts with VLOOKUP, and it assumes two things: you can type a table into a sheet, and you can write a formula. This lesson builds that floor in ten minutes.

Your win todayRead a grid by address, type the employee table, write a SUM, and copy a formula with a locked reference.

The one picture: every cell has an address

Columns have letters, rows have numbers, and a cell is where they meet. A1 is the first cell of every sheet.

Cells and ranges: the addressing system

A cell address is a column letter plus a row number, like a map coordinate: A1, D4. A range is a rectangle of cells, written as top-left : bottom-right. The colon means "to". You will write these constantly, because every function and every lookup takes a range.

You write	It means
`A1`	One cell: column A, row 1.
`A2:D6`	A rectangle from A2 to D6. In the picture above: the whole employee table, without the header row.
`$A$2:$D$6`	The same rectangle with the `$` locks. It survives a copy. This is the range Lesson 1 uses in every VLOOKUP.

Two shortcuts: click a cell and its address appears in the Name Box (top-left). Type an address into the Name Box, and Excel jumps there.

Typing data: the left/right rule

Click a cell, type, and press Enter (the selection moves down) or Tab (it moves right). Excel guesses the type of what you typed, and the guess is visible:

Text sits on the left of the cell. E101, Asha, Sales.
Numbers and dates sit on the right. 52000, 05-Jan.

This alignment is a free health check. If a number sits on the left, Excel stored it as text, and SUM will skip it. In an interview, "why is my total wrong?" often means "one number is stored as text".

The classic beginner trapA formula must start with =. Type SUM(D2:D6) without it, and Excel stores the words, not a calculation. Common causes of text-numbers: a leading apostrophe ('52000), a stray space, or a paste from a web page. To edit a cell instead of replacing it, press F2 or double-click it.

Your first formula, and what a function is

A formula is anything you type that starts with = and calculates: =D2+D3, =D2*$G$2, =(D2+D3)/2. Excel follows normal arithmetic order: multiplication and division before addition and subtraction. Brackets remove all doubt.

A function is a ready-made formula with a name. You call it inside a formula, and it takes a range in brackets:

Function	What it does	On your table (D2:D6)
`=SUM(D2:D6)`	Adds the range	276000
`=AVERAGE(D2:D6)`	Mean of the range	55200
`=MIN(D2:D6)` · `=MAX(D2:D6)`	Smallest · largest	45000 · 70000
`=COUNT(D2:D6)`	Counts the numeric cells	5

Syntax from Microsoft: SUM function. Lesson 3 adds the multi-condition versions (SUMIFS, COUNTIFS) and IF/IFERROR.

Copy it down: relative vs absolute references

You type one formula and copy it down for every row. The references behave in two ways, and this is the whole trick:

Press F4 (Mac: ⌘T) while typing a reference to add or remove the $ signs. Lock a rate, a tax slab, or a target that lives in one cell.

Excel stores 10% as 0.1 and only changes the display. The % button on the ribbon is a format, not a calculation. Same for currency: the value stays a plain number.^[MS]

Error values are clues, not disasters

Error	It means	Typical cause
`#N/A`	The value was not found	A lookup key that does not exist (Lesson 1)
`#DIV/0!`	Division by zero	A blank or zero cell in the divisor^[MS]
`#VALUE!`	Text where a number must be	Arithmetic on a text-number, like `"52000"`
`#REF!`	The reference no longer exists	A row or column it pointed to was deleted

Read the error before you hide it. IFERROR (Lesson 3) replaces the message, and it hides real mistakes just as well as expected ones.

Say it in the interview"A formula is anything I write that starts with an equals sign. A function is a named built-in like SUM or AVERAGE that I call inside a formula. Cell references are relative by default, so they shift when I copy; the dollar signs lock a column or row, so $G$2 keeps a rate fixed when I fill a bonus formula down. And I check alignment: a number sitting on the left was stored as text, and that silently breaks SUM."

Retrieval check

You see A2:D6 in a formula. What does it cover?

You type 61000 and it appears on the LEFT of the cell. Why?

F2 holds =D2*$G$2. You copy it down to F3. The new formula is …

A cell shows #N/A. What does it mean?

What must every formula start with?

Type it

Write the formula for the total salary of D2:D6.

Asha's bonus: salary in D2, rate in G2. Write the formula.

Write the range for the whole table: all four columns, the five data rows, no header.

Your turn

Open Excel or Google Sheets. Type the table from the picture into A1:D6, headers in row 1.
Type =SUM(D2:D6) below the table. Confirm 276000. Now break it: type a space before one salary and watch the total change.
Put 10% in G2. Write =D2*$G$2 in F2 and drag the fill handle down to F6. Check the five results: 5200, 4800, 6100, 4500, 7000.
Type '12345 (apostrophe first) in an empty cell. Watch it go left. Then fix it without retyping.
Make a #DIV/0! on purpose: =D2/0. Read it, then fix it.
Close this page and say the "Say it in the interview" answer out loud from memory.

Go deeper

Primary source: Microsoft Support: Overview of formulas in Excel. Short, official, and it covers operators and reference types. For a slower beginner video course: GCFGlobal: Excel Foundations (free).

💬 Stuck or curious? Ask your teacher. For example: "give me 5 more range-reading exercises" or "why do dates sit on the right?"