A 45-minute crypto lesson plan: teach wallet arithmetic and scam spotting without any real money

One projected practice wallet, one printed worksheet per student, and a pencil. In 45 minutes a class learns how a balance is built, why yesterday is the base of a daily change, and why no screenshot can prove ownership. A scam-awareness session for adults is included.

Published: 24 September 2026 · Last reviewed: 1 November 2026

Most crypto lessons start with blockchains and lose half the room by minute ten. This one starts with something every student can read: a wallet screen. The teacher projects it, the class checks its numbers with pencils, and by the end they know both how the numbers are made and why a picture of them settles nothing.

What you need and what students leave with

Materials fit in a bag: a computer and projector, the worksheet further down, and one printed screenshot per student. Take that screenshot before class from the flexdger.com homepage, whose first screen is a wallet in a phone frame produced by our simulator. Capture it while the balance and all five token rows are visible. Nobody signs in, so no student email or password is ever involved.

Leave the live page out of the exercises. It cannot be edited from the homepage, its prices drift by themselves, and its list scrolls away and back. A paper copy keeps every student on the same numbers and lets one answer key serve the class. The demo is the one place where amounts can be changed (under a DEMO mark), which suits a demonstration, not a graded task. More setups are in wallet screens for demos, decks and lessons.

By the bell, students should be able to do three things:

• Work out a row's value from quantity and price, and rebuild the total with the cash row included.
• Measure a daily change against yesterday's value, then convert it to a percentage.
• Say, in their own words, why a screenshot is not proof, and what to do with a request for a recovery phrase.

The 45 minutes at a glance

Minutes 0 to 6: the trust question

Project the wallet and give the class a minute of silence. Then ask what, on this screen, they believe, and why. Expect answers like the total, the coin names, the green arrows. Write them on the board without comment. You will come back to the list at minute 32, and by then most of it will have been crossed out.

Minutes 6 to 18: rows and totals

A row shows a quantity and a dollar value, but never the price of one coin. Ask students to derive it by dividing the value by the quantity. Then three quick what-ifs: double the quantity and the value doubles, halve it and the value halves, add $500 in cash and the total rises by exactly $500. Finally they sum the five rows plus cash and compare with the figure at the top. A cent or two of rounding is normal.

One sentence goes on the board: row value = quantity × price, total = rows + cash. If you project the live screen, point out that the total changes while nobody touches anything. A balance is computed, not stored, which is the reason a total typed in by hand gives an edited screen away. The anatomy of a wallet portfolio screen labels every part for students who ask.

Minutes 18 to 32: daily change, the part everyone gets wrong

Do an example on the board with invented prices:

• 0.2 BTC: $60,000 yesterday, $63,000 today. The row goes from $12,000 to $12,600 (+5%).
• 4 ETH: $2,000 yesterday, $1,900 today. The row goes from $8,000 to $7,600 (-5%).
• Cash: $400, unchanged.

Yesterday the wallet held $20,400 and today it holds $20,600, so it gained $200, and 200 divided by 20,400 is +0.98%. Two traps are worth naming. Averaging the row percentages gives 0%, which is clearly wrong because money was made. Dividing by today’s total gives 0.97%, close but wrong. The base is always yesterday. Cash also waters the move down: leave it out and the same $200 is +1.00%.

A screen gives today’s value and a percentage, so real practice is going backward: a row worth $12,600 that is up 5% was worth 12,600 divided by 1.05, which is $12,000. Next, on the printed still, students add up the dollar changes of the rows, compare with the change under the total, and divide by the total minus that change. Dollars should agree within a cent or two, and the rounded percentage should match the screen.

Minutes 32 to 41: what a picture proves

Return to the list from minute 0. Nobody in the room owns this balance, the sums all check out, and the screen looks like a finished app. So what does it prove about anyone’s money? Nothing. A block explorer shows what a public address holds, and only a message signed from that address links it to a person. Put students in pairs to run through the tells in how to spot a fake crypto wallet screenshot, using the printed still.

Then the key rule. A seed phrase is 12 or 24 words that rebuild a wallet on any device, which makes whoever holds them the owner, with no reset option. It never goes into a website, a form, a “support” chat, a game or a giveaway. The page on your projector never asks for it, and any page that does is trying to rob you.

Minutes 41 to 45: exit ticket

1. A wallet holds 0.5 BTC and $1,000 cash. BTC was $60,000 yesterday and is $57,000 today. What is the balance, the change in dollars and the change in percent? ($29,500, -$1,500, -4.84%.)
2. Name one thing that can prove a balance and one that never can. (An address on a block explorer plus a signed message; a screenshot.)
3. A page wants your 12 words to “verify” your wallet. What now? (Close it and tell an adult or a teacher.)

Wrong answers to question 1 tell you where the confusion lives: -5.08% means the student divided by today’s total, and -5% means the cash was dropped.

Adjusting for the room

• Middle school: whole numbers, dollar changes only, no percentages.
• High school: the plan as written.
• Adult workshops: compress the math to ten minutes and give the freed time to the proof discussion and the scam session below.

Worksheet and answer key

Every price is invented and stated in the question, so nobody has to look up a market quote.

1. Balance. A wallet shows 0.5 BTC at 60,000 USD, 3 ETH at 2,000 USD and 800 USD in cash. What is the total?
2. Unit price. A row reads 1.5 ETH, worth 3,600 USD. What does one ETH cost?
3. Yesterday. A row is worth 6,300 USD and is up 5% today. What was it worth yesterday, and what is the change in dollars?
4. The whole wallet. The BTC row (12,000 USD) is up 3%, the ETH row (5,000 USD) is down 4%, and 500 USD of cash did not move. What is the wallet’s change in dollars and in percent?
5. Proof. A screenshot shows 9 ETH. True or false: whoever posted it owns 9 ETH. Answer in one sentence.

Answer key.

1. 30,000 + 6,000 + 800 = 36,800 USD.
2. 3,600 / 1.5 = 2,400 USD.
3. 6,300 / 1.05 = 6,000 USD yesterday, so the change is +300 USD. Taking 5% of today’s 6,300 would give 315, which is the common mistake.
4. BTC yesterday: 12,000 / 1.03 = 11,650.49, a gain of 349.51. ETH yesterday: 5,000 / 0.96 = 5,208.33, a loss of 208.33. Net +141.18 USD. Yesterday’s total was 17,358.82, so the change is +0.81%.
5. False. A screen can display any number; funds are tied to a person only by an address on a block explorer plus a message signed from it.

A scam-awareness session built on the same screen

The wallet that taught arithmetic also works for a security briefing with employees, teenagers or older relatives. What the research says about format is useful. In a randomized trial by the FINRA Investor Education Foundation and USC, a three-minute video or short text on common fraud tactics reduced willingness to invest in fraudulent pitches by 42% (video) and 44% (text), compared with a control group. After six months, people trained once did no better than the control group, while those given a second session at the three-month mark were still 10% less willing. So keep sessions short, and plan on a repeat.

A ten-minute module each, one screen and one rule per module:

1. The balance that only goes up. A dashboard whose profit climbs until a fee appears to withdraw. Rule: a number on a site someone sent you to is not money you hold, and a fee to withdraw means stop.
2. The helpful caller. Someone you did not contact describes a problem with your account and asks to see your screen. Rule: hang up and use the official website.
3. The “verification” page. It asks for the 12 words. Rule: no honest service wants them.
4. The screenshot flex. A post showing a giant balance. Rule: it proves nothing, as spotting a fake wallet screenshot shows.
5. The payment method. The FTC puts it bluntly: “Only scammers demand payment in cryptocurrency.”
6. The rescuer. A stranger offers to recover your lost money for a fee. Rule: the FTC says that after a loss you are likely to find nobody can step in to get your funds back, so the offer is a second scam.

A true-or-false round makes a good closer, and every answer is false:

1. A site shows a 40% gain in a month, so the money is yours.
2. They let you withdraw a small amount, so the platform must be genuine.
3. A fee to release your withdrawal is routine.
4. A caller who knows your name and the exchange you use is legitimate.
5. A screenshot of a large balance means that person made money.

Tailor the delivery. For employees, finish with the reporting route on a slide. For students, begin with social media and the “mentor” who suggests moving to a private chat. For older adults, lead with modules 2, 5 and 6 and rehearse the hang-up line aloud.