A formula starts with equals · Martinとコード

The golden rule

Type A1+B1 into a cell — you will see the text A1+B1. The spreadsheet thinks you wrote a sentence.

Type =A1+B1 — you will see a sum. Equals says: count this.

When you change A1, the result recalculates. That is why a spreadsheet exists. Word cannot do that. A calculator can, but it does not remember that the number lives in A1.

Do it on numbers, so it is not just a sentence in a lesson.

Open sheet メモs. If A1 is full from last time, start from row 10, so you do not mix the exercise with days. Cleaner is column G: G1, H1, I1.
In G1 type 3. In H1 type 5. Enter.
In I1 type G1+H1 without equals. Enter. In I1 the text G1+H1 lights up. The spreadsheet did not count. The text sits on the left.
Click I1. Delete. Type =G1+H1. Enter. In I1 8 lights up. The number sits on the right.
Click I1 again. In the cell you see 8. In the formula bar you see =G1+H1. That matters: on the screen the result, in the formula bar the recipe.
Change G1 to 10. Enter. I1 must jump to 15. If it stays 8, in I1 there is no formula, but a hard eight.

💡

You can type a formula in the formula bar at the top, or straight in the cell. Always start with =. In Excel and in Sheets it is the same. After = click G1 with the mouse — the spreadsheet writes G1. Type +. Click H1. Enter. You do not have to tap addresses blind.

Add, subtract, times, divide

You want	Type	Example G1=10, H1=5	You see
sum	`=G1+H1`	10 + 5	15
difference	`=G1-H1`	10 − 5	5
times	`=G1*H1`	10 × 5	50
divide	`=G1/H1`	10 ÷ 5	2

A star is times. A slash is divide. On the keyboard a star is often Shift+8, a slash next to Shift on the right. Brackets work like in maths: =(G1+H1)*2 is 30, not 20. Without brackets =G1+H1*2 is 10 + 10 = 20, because times comes first.

Try a difference too, so it is not only plus.

In I2 type =G1-H1. Enter. With G1=10 and H1=5 you will see 5.
In I3 type =G1*H1. Enter. 50.
In I4 type =G1/H1. Enter. 2.
In I5 type =(G1+H1)*2. Enter. 30.

Click I5. The formula bar must start with =. If you see 30 and nothing more, you typed the result by hand. Delete and type the formula.

⚠️

If you see #VALUE!, you are adding text to a number. For example G1 is 10 points. If you see the formula itself as text (=G1+H1 in the cell, aligned left), equals is missing or the cell is formatted as text, or you put a space before =. If you see #DIV/0!, you divide by zero — H1 is 0 or empty.

A space before equals and other traps

The most common bug: =G1+H1 with a space before equals. Sheets often takes it as text. Delete the cell, start with equals at once.

Second: =G1 + H1 with spaces around plus. That is fine. Spaces inside a formula do not bother the spreadsheet.

Third: =g1+h1 in small letters. The spreadsheet takes it. Addresses are not case-sensitive. =G1+H1 is the same.

Fourth: you type =A1+B1, but the numbers are in G and H. Result 0, because A1 and B1 are empty or text. Watch where you click.

Mini pocket money — one day

A formula is not only an exercise in G and H. It is useful on real numbers.

On sheet Pocket (if you have it from Cell kid) try one day by hand. We do not drag a week yet — that is the third Formula kid lesson.

An example for Monday:

B2 (In) = 50
C2 (Spent) = 20
D2 (Left) = =B2-C2

Enter. In D2 you will see 30. Change C2 to 45. D2 jumps to 5. Change C2 to 60. D2 shows −10. Minus is not an error. It says: you spent more than came in.

If D2 shows =B2-C2 as text, equals is missing or D2 is text. If it shows #VALUE!, in B2 or C2 there is a word (fifty).

🏫 Grade average — not SUM yet

On Grades do not add the whole column yet. That will be SUM next time. Here you could type =B2+B3+B4 and it would work — but with ten subjects it becomes a tangle.

If you want to prove equals lives on grades too: in C2 type =B2+0. You will see the same number as in B2. Change B2, C2 moves. Then delete C2. You do not need column C on grades yet.

Now you 💪

Prove that equals lives. Two numbers, a sum next to them, a recalculation.

Somewhere next to each other (for example G1 and H1, or two free columns) you have two numbers. Not words.
Next to them a formula =…+…. In the cell is a sum, in the formula bar a recipe with =.
Change the first number. The sum moves. If it does not, in the “sum” is a hard number — delete and type the formula again.
Second exercise: next to it type =…-…. The difference sits. On pocket money in D2 feel free =B2-C2 and in D2 you see 30 (with 50 and 20).
Click the cell with the result. Say out loud what is on the screen and what is in the formula bar. They must be two different things: a number vs =.

✅

Check: In the cell is a number. You click it — in the formula bar is =…. You change an input, the result moves. Without = you would see text.

What to take from this lesson

Without = it is text. With = it is a calculation. A space before = kills the formula.
On the screen the result, in the formula bar the recipe. If both show 8, the formula is not there.
* times, / divide, + plus, - minus. Brackets like in maths.
The result recalculates when you change an input. That is why you point at cells, not a hard number.
#VALUE! = text instead of a number. #DIV/0! = you divide by zero.