Shopper stacks filters, not a haul of discounts
The finale: you can compare two prices, ask 50% off what, read the till not a sign without VAT, add postage, translate a game into Kč, multiply a subscription, know about a return, hide a receipt, say tomorrow, hold a list, write regret.
That is not Excel. That is a decision at a sign. Planner will want a trip. With no filters a trip will be eaten by a discount on a souvenir.
Vojta: ten screenshots of discounts. Amálie: one list ceiling 60, one sentence tomorrow, one bridge 199>80. Amálie is Shopper. Vojta is a board.
A cheat sheet into the notebook, not onto Discord: unit · base · till · +postage · bridge Kč · ×month · paper · tomorrow.
Eight filters, one envelope
Each filter can say no. An envelope can say no even when filters shout yes. Order: first the truth of the number, then the envelope, then a parent’s lock. Three gates.
What does not belong here: a ranking of who bought more, a tax return, getting around a PIN, an email for a discount.
Sceptic later adds a scam. Shopper adds a decent shop that still pushes. Both paths hurt the balance. One lies more.
Zero pocket money: still Shopper. You can do filters on practice numbers and on “not from mine”. A certificate in the head is not a bowl of coins.
Amálie wants to shorten it to “it will be fine somehow”. Vojta asks what the lesson Shopper finale is for, when a table can do a sum. A sum does not count respect, a PIN, a trap or an envelope. The core is: Shopper has filters and an envelope. A discount without them is a sign.
Adults pay the rent. The card, the account and the PIN belong to a parent. A child’s email does not belong here. Pocket-money numbers do not belong on the network. If you break these rules in the lesson “Shopper finale”, you know a word, not the course.
Amálie’s cheat sheet eight words. Vojta SUM of discounts 2000, envelope 0. Discounts won the board. The balance did not. The finale takes the cheat sheet.
Practice numbers, not a bank statement. Amálie has 80 Kč in the want envelope. Vojta pushes a step this lesson can name. When Amálie uses the core, either it waits for a parent, or it fits the envelope. If not, anger and a hole are left — proof of pressure, not that the lesson is pointless.
Do not contest the biggest class discount. That is a ranking with percents. Let a teacher see a list and a sentence, not a haul.
Why this right now
You are in the course Money with Martin, level Shopper. You can write numbers in a notebook or a table, but the topic is money and decisions, not Excel formulas. The account, the card and the PIN belong to a parent. A child’s email does not belong here. Do not put pocket-money numbers on the network.
This is not the Sheets with Martin course. A table may help, but the mark of success is a decision, not SUM.
You will know this lesson by one sentence: Shopper has filters and an envelope. A discount without them is a sign. When you can say it to a parent or a teacher, you have the core. The rest is practice, not magic.
Planner, Banker, Sceptic, Till boss. All reach into spending. Shopper taught you to read spending. Next you learn a plan, a card, a trap, a stall.
If you skip this, the next lesson in level Shopper will stand on fog. A cheat sheet is in the notebook. A list with a limit lives. Numbers are not on the network. It is not a test for marks. It is a safety net, so “Shopper finale” is not only a heading.
Four things you will build from the course
The course has four small projects. You do not have to do them all at once. Today you add only what this lesson can do.
🪙 Pocket money
A 14-day record: income, spending, balance. What you do not write down is as if you did not spend it — and that is a lie.
Pocket money: filters by every bigger row.
🚌 Class trip
A budget, a reserve, a plan B. A shared till has rules.
A trip: filters on a souvenir and “free” entry.
🎮 Game shop
V-bucks and a loot box are a purchase. A subscription keeps going.
A game: a bridge + a subscription + pressure = three filters at once.
🧾 Stall / mini-company
Cost, price, profit. Three numbers for the class.
A stall: filters on your sign too. Do not lie with a unit.
Workshop: a cheat sheet of eight words
Eight words in your own words. Show a parent. Do not photo with amounts.
-
Write eight filters. One example not by each — only a word, so it fits in the head.
-
One envelope: even a yes from filters may be no.
-
Tick the list project: was there paper?
-
A sentence into Planner: “A trip has a ceiling, not a discount haul.”
You count with a cheat sheet, not with a pile of boxes. Boxes with no filters are Prep about value you did not use.
Pocket money: Pocket money: filters by every bigger row. Do not write someone else’s amount, a PIN, an IBAN or “how much a classmate gets” next to it. A rule and a practice number are enough — or an honest zero.
Class trip: A trip: filters on a souvenir and “free” entry. Do not write someone else’s amount, a PIN, an IBAN or “how much a classmate gets” next to it. A rule and a practice number are enough — or an honest zero.
Game shop: A game: a bridge + a subscription + pressure = three filters at once. Do not write someone else’s amount, a PIN, an IBAN or “how much a classmate gets” next to it. A rule and a practice number are enough — or an honest zero.
Stall: A stall: filters on your sign too. Do not lie with a unit. Do not write someone else’s amount, a PIN, an IBAN or “how much a classmate gets” next to it. A rule and a practice number are enough — or an honest zero.
What to tell a parent with no wage and no account number: “Today I went through Shopper finale — Shopper has filters and an envelope. A discount without them is a sign.” If they have no time, a slip in the notebook is enough. Stories and class chat are not enough.
I can name eight filters. If you cannot see this, let the next lesson wait. It is not shame. It is a hole in the chapter, not in you.
Practice: which filter?
Match a trick to a filter.
-
0.5 l vs 1 l. Filter?
-
−50% with no base. Filter?
-
A pass timer. Filter?
-
49 Kč / month. Filter?
Now you 💪
Go through three checks. By each one, tick in your head: do I see it, or not?
- I can name eight filters.
- An envelope is the last gate before a parent’s lock.
- A haul of discounts is not a finale.
If something is missing, go back to the steps above. It is not a test for marks. It is a safety net, so you go on with certainty, not with a mess.
Check: A cheat sheet is in the notebook. A list with a limit lives. Numbers are not on the network.
What to take from this lesson
- Shopper reads a sign in layers.
- An envelope may say no even to a bargain.
- Digital and a rhythm are spending.
- Next: a trip plan, not a bigger shopping fever.
- Names in the examples (Amálie, Vojta) are made up. Do not put your number, email or photo here.
- Next lesson: When you can do this, go to the next lesson in the same level.
© 2026 Ing. Martin Polak / AlgoRhino · Content usage terms