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Why does = make a cell calculate?

# Spreadsheets in 10 minutes A **spreadsheet** is a grid of **cells**. Each cell has an address like **A1**, **B2**. Examples: Excel, Google Sheets. ## Why students love it - Marks list - Pocket-money tracker - Science experiment table - Attendance ## Magic formulas If A1 is 10 and A2 is 5: - `=A1+A2` → 15 - `=SUM(A1:A10)` adds a range - `=AVERAGE(B2:B8)` finds the mean Fill-down copies a pattern. Charts turn numbers into bars you can actually see. > The `=` sign tells the sheet “calculate this”, not “just show text”. ## A tiny marks book (build this once) | | A | B | | --- | --- | --- | | 1 | Name | Marks | | 2 | Asha | 18 | | 3 | Dev | 16 | | 4 | Mia | 20 | | 5 | Total | =SUM(B2:B4) | | 6 | Average | =AVERAGE(B2:B4) | Change Mia to 17. Watch B5 and B6 move. That is a **live model**, not a dead picture of numbers. ### Formula vs value - Value: `18` - Formula: `=B2+1` The sheet stores the formula and shows the result. Click the cell and look at the formula bar to see the truth. ### Charts Select the names and marks → Insert → Column chart. Suddenly the class can *see* who needs help. Charts are output of the same grid.

By the end of this lesson

Read a cell address, start a formula with =, and use SUM / AVERAGE on a small marks table.

Remember

  • A spreadsheet is a grid of cells. B3 = column B, row 3.
  • Formulas start with =. =A1+A2 adds those two cells.
  • =SUM(A1:A10) adds a range. =AVERAGE(B2:B8) is the mean.
  • Fill-down copies a pattern. Charts turn numbers into bars.
  • = means “calculate”, not “show this text”.

Worked examples

Cover the answer. Try the steps on paper, then open them.

Example 1 — Address drill

Where is C1? Where is A4?

  1. C1 — third column, first row (top)
  2. A4 — first column, fourth row

Answer: C1 top of column C ; A4 down column A

Check: Letter = column, number = row.

Example 2 — Marks total

A2=18, A3=16, A4=20. Total in A5.

  1. Click A5
  2. Type =SUM(A2:A4) or =A2+A3+A4
  3. Enter → 54
  4. If a mark changes, A5 updates

Answer: 54

Check: That live update is why we use sheets.

Example 3 — Mean

Same three marks. Average in A6.

  1. =AVERAGE(A2:A4)
  2. 54 / 3 = 18

Answer: 18

Check: AVERAGE is the arithmetic mean.

Common mistakes

Slip Typing SUM(A1:A10) without =.

Fix The sheet shows the text SUM(…) and does not add.

Always start with =.

Slip Writing A1 + A2 in a cell as words without =.

Fix Same problem — it is text.

=A1+A2.

Slip Mixing column and row: thinking 3B is a cell.

Fix It is B3. Letter first in Excel/Sheets.

B is the street, 3 is the house number.

Try on paper first

Write the answer, then tap Reveal. These are not the quiz — they are warm-ups.

1. Cell D7 is column ? row ?

Answer: D and 7

2. Write a formula that adds B1 and B2.

Answer: =B1+B2

3. What does SUM do?

Answer: Adds a range of numbers

4. What does AVERAGE find?

Answer: The mean

Touch practice

9 tap / type

Tap or type. Use the hint if you need it. Retry any miss — the why is the lesson.

Optional picture lab

After practice

Real world

Marks lists and pocket money.

Connect

Formulas are tiny programs.

⭐ Star quiz

9 questions

Do the worked examples and touch practice first. Then take the quiz without peeking.

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