Cells and Your First Formula
About this lesson
Every cell has an address: its column letter and its row number. B4 is column B, row 4.
- read any cell's address from its column letter and row number.
- write a formula that points at a cell, so it updates when the cell does.
- multiply and add cells together in one formula.
The idea
A formula starts with an equals sign. After it, you can type a number. But the useful thing is to type a cell address instead. =B2 means "show what is in B2". You can do maths with addresses. A star (*) multiplies, a slash (/) divides, plus adds and minus subtracts. Excel multiplies before it adds.
The most common first-day mistake is typing the number you can see, not the address of its cell. Today =4.5 and =B2 show the same thing. Next month the price changes. Only =B2 is still right. That is the whole reason spreadsheets exist.
The mistake to watch for
People type the number they can see instead of the cell address. It looks right today. When the price changes, the number is wrong, and nothing shows you which cells were typed by hand. Always start with an equals sign and a cell address. Then the cell updates by itself.
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Every cell has an address: its column letter, then its row number. Column letters run along the top. Row numbers run down the left. So the cell in column B, row 4 is B4.
Click the cell that holds the price of a chain.
| Row | A | B | C | D | E | F | G |
|---|---|---|---|---|---|---|---|
| 1 | Part | Price | In stock | ||||
| 2 | Inner tube | 4.5 | 26 | Chain price | |||
| 3 | Brake pad | 12 | 8 | ||||
| 4 | Chain | 24.99 | 5 | Chain stock value | |||
| 5 | Saddle | 38.5 | 3 | ||||
| 6 | Chains and saddles | ||||||
| 7 | |||||||
| 8 |
Every step
-
Every cell has an address: its column letter, then its row number. Column letters run along the top. Row numbers run down the left. So the cell in column B, row 4 is
B4. Click the cell that holds the price of a chain. -
A formula starts with an equals sign. The simplest formula points at a cell. In
E2, type=B4. The equals sign tells Excel "this is an instruction".B4means "show what is inB4". -
Read
=C4and say what it would show.C4is the chain's row in the In stock column. -
Formulas can do maths with cells. A star (*) multiplies. In
E4, work out the value of all the chains in stock. That is the price inB4times the count inC4. -
One formula can do more than one calculation. Excel multiplies before it adds. In
E6, add the value of the chains to the value of the saddles. Each value is price times stock. Join the two with a plus sign. -
Here is why a formula beats typing the number. Tomorrow the chain's price goes up to 30, so
B4becomes 30.E2still holds=B4. What doesE2show now?