Currency: Kč and the euro · Martinとコード

Ten koruna is not ten euro

Currency is the name of a token. In Czechia we use the koruna (Kč) every day. In part of ヨーロッパ the euro (€). The same number 10 by one token and by the other is not the same agreement. That is why on a trip you do not mix up a “ten” with no name.

The course does not teach you an exchange office by heart. It teaches you to write the unit. 50 without Kč or € is half a sentence. Like saying “I have ten” and not saying ten of what.

Sofie sees ice cream for 3 by the sea. She thinks: “Three koruna, almost free.” It is 3 €. Matyáš shouts “take two!” Sofie would pay from pocket money that lasted a week at home and here for two scoops.

At home Matyáš sees a price 25 Kč for juice. That is his world. On a trip he sees 25 with no token on a handwritten sign. He asks: “Kč, or euro?” The seller points to €. Matyáš walks away. He is not mean. He finished reading the unit.

💡

On a sign look for Kč, €, or the word euro / koruna. If it is missing, ask. Do not guess from how the writing looks. Guessing the unit is dearer than asking awkwardly.

The unit belongs with the number

A number without a unit is like an address without a city. 10 can be 10 Kč (small change) or 10 € (already a fair spend from pocket money). The conversion changes. That is why the course does not give a magic number “times 25” as an eternal truth. It says: look at which token this stall takes, and ask a parent how much that is in koruna today, when you need it.

You will sometimes see the euro in Czechia at petrol stations or in a web shop. That does not mean you pay in euro from your pocket. Often it is only information. Payment can still go in koruna from a parent’s account. Wrapper and token again.

A foreign currency is not “better”. It is not a traveller’s badge. It is another agreement. The mockery “it’s only three euro” ignores that three euro is not three koruna. The mockery “it’s only a twenty” in euro would be an even worse mistake.

With a game in euro (a price in € in a shop) the same password holds: a parent approves. The currency changes. The lock does not.

Sofie wants to shorten it to “it will be fine somehow”. Matyáš asks what the lesson Currency: Kč and the euro 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: A unit belongs with a number. Ten koruna is not ten euro.

Practice sign A: juice 30 Kč. Sign B: juice 2 €. Sofie does not know the rate by heart. She knows that 2 € ≠ 2 Kč. She asks a parent: “Is that more, or less than a thirty?” A parent says. Sofie decides. She does not decide from the feeling “a two is small”.

Matyáš writes only purchases in Kč in the notebook. When a parent once pays in euro, Matyáš writes: “ice cream — 3 € (a parent paid)”. With no conversion, if he does not know it. Honesty of the unit is more than a fake conversion.

⚠️

An exchange office, a kiosk “a good rate” and a person who will swap coins with you in the street is not a teacher. A parent changes currency. You ask about the unit, you do not go swap pocket money with a stranger.

Why this right now

You are in the course Money with Martin, level 準備. 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: A unit belongs with a number. Ten koruna is not ten euro. When you can say it to a parent or a teacher, you have the core. The rest is practice, not magic.

A class trip and a web shop can show a foreign token. Without a unit, comparing prices in Shopper fails. With a unit you know you should ask, not guess.

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.

Write pocket money with Kč. Without a unit the record is half.

🚌 Class trip

A budget, a reserve, a plan B. A shared till has rules.

A trip abroad: a budget in one currency, so tens do not get mixed up.

🎮 Game shop

V-bucks and a loot box are a purchase. A subscription keeps going.

A game shop may write dollars or euro. A parent still approves it.

🧾 Stall / mini-company

Cost, price, profit. Three numbers for the class.

A stall at school: a price in Kč. “Three euro” as a joke spoils the sign.

Workshop: add the unit

You will find three numbers from a real day (a sign, a shop window, a notebook) and add Kč or “I don’t know — I will ask”.

Three numbers on paper. By each a unit, or a question mark. No made-up rate from your head “so I look clever”.
One sentence out loud: “I do not take ten with no currency name.”
With a parent: where would you see the euro on a trip? Only an example, not a plan to exchange.
In the pocket-money notebook check that amounts have Kč.

You count when a question mark by a unit is more acceptable than a made-up number. A rate from an advert on a machine is not your homework.

Practice: which token?

Decide. You are not playing exchange clerk.

A sign “water 2”. What do you do first?
Why is 10 € not 10 Kč, even if both start with a ten?
A web shop shows € and then a price in Kč at a parent’s checkout. Why look at the second one?
A friend in the street: “I’ll swap your change for euro at a good rate.” Why not?

Now you 💪

Go through three checks. By each one, tick in your head: do I see it, or not?

I can add a unit to a number, or ask.
I know the same number in Kč and in € is not the same agreement.
I do not change currency in the street with a stranger.

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: Three numbers have a unit or a question mark. In the pocket-money notebook there is Kč.

What to take from this lesson

Currency is the name of a token. It belongs with the number.
Ten koruna ≠ ten euro.
A parent says the conversion, not an automaton from your head.
An exchange with a stranger does not belong here.
名前s in the examples (Sofie, Matyáš) 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.