1.2First formulas: + − × ÷ & order of operations
The essentials in 30 seconds
- Everything starts with =: without =, Excel displays text; with =, references (B2), numbers and operators (+ − * / ^) calculate — and referencing cells makes the calculation alive.
- A strict order: parentheses first, then power ^, then × and ÷, finally + and − — =2+3*4 equals 14, not 20.
- Parentheses for comfort: even when optional, they guarantee the intended calculation and make the formula re-readable by Wassim as by his client.
Running mini-case — Wassim quotes a discount
Wassim must apply a 10% discount to a client's fees: price in B2, discount in C2. Instead of typing the result by hand, he writes =B2*(1-C2) — the parentheses force the discount before the multiplication. When the client negotiates 15%, Wassim changes a single cell and the whole quote recalculates. A living formula, zero retyping.
Continuation of case 1.1 — Wassim moves from cleaned data to the first living calculations.
1. Every formula starts with =
A formula always starts with =, otherwise Excel displays text. You combine references (A1, B2), numbers and operators: + - * (×) / (÷) ^ (power). Referencing cells rather than typing numbers is what makes the calculation alive.
Wassim never types an amount hard-coded in a client formula: the price lives in B2, the rate in C2, the formula reads both — if the data changes, the result follows.
2. The order of precedence
Excel follows an order: first parentheses ( ), then powers ^, then × and ÷, finally + and −. Thus =2+3*4 equals 14 (3×4 first), not 20. To force another order, you add parentheses: =(2+3)*4 equals 20.
Wassim's case: =B2*(1-C2) — without parentheses, =B2*1-C2 would subtract the discount instead of applying it. One parenthesis = a correct quote.
3. Writing readable formulas
Prefer references over hard-coded values, and parentheses to remove any ambiguity even when not strictly necessary — this makes the formula re-readable. A short, clear formula beats a «clever», unreadable one.
Read it aloud: «price times one minus discount» must match what you read in the formula bar. If not, rewrite it.
🔎 Concrete example — 🔎 Concrete example — 2 + 3 × 4: 14 or 20?
Two formulas that seem close, two results:
=2+3*4 → 14 (× before +)
=(2+3)*4 → 20 (parentheses first)
=B2*(1-C2) → discount C2 applied to price B2Reading: without parentheses, × and ÷ come before + and −.
Lesson: a well-placed parenthesis guarantees the intended calculation and the re-reading.
Section vocabulary
- Formula
- An expression starting with = that computes a value from references, numbers and operators.
Simple example: =B2*(1-C2) computes the discounted price at Wassim's.
What it is not: a text that starts without = and displays as is.
Reflex: no = visible in the bar = not a calculation.
- Operator
- Calculation symbol: + − * (×) / (÷) ^ (power).
Simple example: * applies the discount, ^ computes a power.
What it is not: a named function like SUM.
Reflex: * and / are typed on the keyboard, never × ÷.
- Reference
- A cell address used in a formula (B2, C2); makes the calculation alive.
Simple example: C2 holds the discount: changing C2 recalculates everything.
What it is not: a number typed hard-coded in the formula.
Reflex: aim at cells, not numbers.
- Order of operations
- Order: parentheses, power, × ÷, then + −.
Simple example: =2+3*4 equals 14; =(2+3)*4 equals 20.
What it is not: a strictly left-to-right calculation.
Reflex: doubt = parentheses, even «for nothing».
In practice — In practice — Check the calculation order
- Write =2+3*4 then =(2+3)*4 and compare (14 vs 20).
- Compute a discount: =Price*(1-Discount) with Price and Discount in cells.
- Compute an increase: =Base*(1+Rate).
- Add «comfort» parentheses to make a long formula readable.
Ready-to-say script — justifying a formula to the client (30 s)
« The price is in B2, the discount in C2, and the formula =B2*(1-C2) applies the discount before multiplying — the parentheses force the order. If the discount changes, I edit C2 and the whole quote recalculates, without retyping. »
Say it while showing the formula bar and changing C2 live.
Copy-paste template — discount and increase
=B2*(1-C2) Discount: price B2, rate C2 (e.g. 0.10)
=B2*(1+C2) Increase: base B2, rate C2 (e.g. 0.05)
=(B2+C2)*D2 Force the addition first with ( )Wassim's discount
As above: =B2*(1-C2) — 10% then 15% with no retyping, a single modified cell.
Price increase
=B2*(1+C2) with C2 = 0.05: +5% applied to the whole column by copying.
Simple tax-inclusive total
=B2*(1+C2) with C2 = 0.19: the net plus 19% — the parenthesis guarantees (1+rate) before the multiplication.
One-off power
=B2^2 for a square: ^ comes before × and ÷ — and parentheses remain mandatory to force another order.
✓ Best practices
- Start every formula with =.
- Reference cells rather than hard-coded numbers.
- Add parentheses for clarity.
✗ Common pitfalls
- Forgetting the = → the formula stays text.
- Believing the calculation is done «left to right».
- Stacking operators without parentheses → surprising result.
Key takeaways
- A formula starts with =.
- Order: parentheses → power → × ÷ → + −.
- =2+3*4 = 14; =(2+3)*4 = 20.
- Referencing cells makes the calculation alive and re-readable.
48h challenge — apply tomorrow
Replace three hard-coded values in your formulas with references, add the parentheses that force the intended order and test =2+3*4 vs =(2+3)*4.
- I start each formula with =.
- I follow the order parentheses → ^ → × ÷ → + −.
- I aim at cells for a living calculation.
Frequently asked questions
My formula displays as is (=A1+B1) instead of the result?
The cell is probably in Text format, or the = is missing at the start. Switch the cell to General and retype the formula starting with =.
Why reference cells rather than typing the numbers?
Because the calculation becomes alive: if the data changes, the result follows. A hard-coded value freezes the calculation and reintroduces errors on every change.
What is =2+3*4 worth in Excel?