Digital wallets

Name:

Date:

Class:

Quick Questions

Shade in the A or B circle for each question.

1. What is a digital wallet?

A An app or software that stores your digital currency and is used to send and receive it

B A leather case that holds coins and notes

2. Where can a digital wallet be stored?

A On a phone or a computer

B Only inside a bank vault

3. Which action can you do with a digital wallet?

A Print new coins and notes

B Send and receive digital currency payments

4. What does a digital wallet hold that lets you use your currency?

A A paper copy of every transaction in the world

B The access details to your digital currency

5. A student loses their phone and has no way into their wallet. What could happen?

A They could lose their digital currency

B Their currency is always safely returned automatically

Match the Pairs

Draw a line connecting each item on the left to its match on the right.

Left column		Right column
1wallet.send("Sam", 0.5)		AA digital wallet is software or an app, not a physical purse that holds coins and notes
2balance = wallet.getBalance()		BSends 0.5 units of digital currency from the wallet to another person
3A digital wallet is an app on a phone or computer that stores a person's digital currency		CLosing access to a wallet can mean losing the digital currency stored in it
4A wallet is used to receive payments as well as send them		Dwallet = WalletApp("phone")
5wallet = "physical leather purse"		Ewallet.receive("Ana", 2)
6lostPhone -> currency is always safe		FChecks how much digital currency the wallet gives access to

Definitions

digital wallet

Fill in the Blanks

Complete each line of code by filling in the missing parts.

____(wallet, "Sam", 5)

balance ← balance _ payment

IF balance __ amount THEN SEND(wallet, "Sam", amount) ENDIF

IF phoneLost THEN access ← _____

wallet ← ____(privateKey)

Spot the Error

Shade in the letter of the line that contains an error.

Question 1

A wallet ← OpenWallet("Sam")

B balance ← wallet.Send()

C OUTPUT "Balance: ", balance

Question 2

A balance ← 50

B balance ← balance - 10

C OUTPUT balance

Question 3

A friend ← "address_77X"

B amount ← 5

C wallet.Receive(friend, amount)

Question 4

A OUTPUT "Enter your password"

B INPUT password

C IF password <> wallet.key THEN

D wallet.Open()

E ENDIF

Question 5

A backup ← wallet.key

B phone ← "lost"

C wallet.Restore(phone)

Answer Key

Digital wallets

Section A: Quick Questions

A — An app or software that stores your digital currency and is used to send and receive it

A — On a phone or a computer

B — Send and receive digital currency payments

B — The access details to your digital currency

A — They could lose their digital currency

Section B: Match the Pairs

wallet.send("Sam", 0.5) → Sends 0.5 units of digital currency from the wallet to another person

balance = wallet.getBalance() → Checks how much digital currency the wallet gives access to

A digital wallet is an app on a phone or computer that stores a person's digital currency → wallet = WalletApp("phone")

A wallet is used to receive payments as well as send them → wallet.receive("Ana", 2)

wallet = "physical leather purse" → A digital wallet is software or an app, not a physical purse that holds coins and notes

lostPhone -> currency is always safe → Losing access to a wallet can mean losing the digital currency stored in it

Section C: Definitions

digital wallet — Software or an app on a phone or computer that stores a person's digital currency and is used to send and receive it. Losing access to it can mean losing the currency.

Section D: Fill in the Blanks

SEND(wallet, "Sam", 5)

balance ← balance + payment

IF balance >= amount THEN
  SEND(wallet, "Sam", amount)
ENDIF

IF phoneLost THEN access ← FALSE

wallet ← OPEN(privateKey)

Section E: Spot the Error

B — To check how much currency the wallet holds you read its balance with wallet.GetBalance(). Send() is used to pay someone, not to read the balance.

B — Receiving a payment adds currency to the wallet, so the line should be balance ← balance + 10. Subtracting is what happens when you send.

C — The program is paying a friend, so it must use wallet.Send(friend, amount). Receive is used when money arrives in your wallet.

C — The wallet should only open when the password matches the key. Using <> would let in people who enter the wrong password, so it should be =.

C — A wallet is restored on a new device using the saved backup key. The lost phone cannot be used, so it should be wallet.Restore(backup).