Today you will
- add formulas to your budget that answer real questions about your project
- write one sentence beside each formula about the decision it helps with
- save {{code:05_ka1_best_spreadsheet}} and a PDF of it
This is Key Assignment work.
If you can't find {{code:05_project_budget}} or your gap-check notes, tell your teacher now.
Warm-up
If someone asked you, "Can I afford one more item?", could your spreadsheet answer at a glance?
A decision-ready formula answers a real question about your project.
A formula earns its place if you can say in one sentence what decision it helps you make. If you can't, delete it.
A mini-table is a small second table, like money coming in, that you check against your costs.
Example
Ciara sells tote bags at a market. Her Remaining formula is budget limit minus total cost. If her stall fee goes up, she sees at once if she can still afford it.
You will build a small budget for Ciara's tote-bag stall at the Saturday market. Follow the steps in the box below.
Everyone does the steps up to the IF flag. Only do the Stretch steps when your teacher says so.
Row 1 headings
| Item | Category | Cost (€) | Flag |
Ciara's costs (rows 2 to 9)
| Item | Category | Cost (€) |
|---|---|---|
| Blank tote bags × 30 | Materials | 45 |
| Fabric paint set | Materials | 18.5 |
| Market stall fee | Venue | 35 |
| Canva Pro (1 month) | Marketing | 12.99 |
| Price tags | Materials | 4.5 |
| Transport | Travel | 12 |
| Business cards | Marketing | 15 |
| Display stand hire | Venue | 20 |
Stretch: Ciara's funding (rows 18 to 20)
| Source | Amount (€) |
|---|---|
| Savings | 80 |
| Part-time wages | 70 |
| Family help | 40 |
Common snags
- If your percentages show {{code:#DIV/0!}}, the $ signs are missing. The formula should be {{formula:=C2/$C$10}}.
- If IF shows {{code:#NAME?}}, start the formula with = and type straight quotes, not curly ones.
- If Remaining doesn't change when you edit a cost, make it subtract the Total cost cell, not a typed number.
Independent Practice
- Open {{code:05_project_budget}} in {{code:05_budget}} and have your gap-check notes beside you.
- Add at least two formulas that close your gaps, such as Remaining or an IF flag.
- Beside each formula, type one sentence about the decision it helps with.
- Delete any formula you can't write a sentence for.
- Rename this file {{code:05_ka1_best_spreadsheet}}, then save a one-page PDF of it in the same folder.
If you rebuilt your budget today, SUM and Remaining are enough.
- My file is called {{code:05_ka1_best_spreadsheet}}.
- My results update when I change a cost.
- Each formula has a decision sentence beside it.
- {{code:05_ka1_best_spreadsheet.pdf}} fits on one page.
Unlock the full learning experience
You're previewing this lesson. Get full access to this lesson and hundreds more — each one ready to teach, with interactive activities, printable resources and pupil progress tracking built in.
This lesson is copyright of Coding Ireland 2017 - 2025. Unauthorised use, copying or distribution is not allowed.