Remember: A digital wallet is a note of who owns how many coins. Sending changes two notes. The lock-code stays in the family. These are made-up coins in a made-up market.
Read and answer
Read the story first, then answer.
The Wallet BoardAt the Pebble Hill market there was a new idea, the Wallet Board. Nobody carried coins any more. Instead each person had a line on a big board with a name and a number, like Maya, 20, and Cy, 0. The number is not coins to touch. It is a note of what is yours, called a digital wallet. When Maya sends Cy ten, no coin travels anywhere. The keeper changes two notes: Maya's drops to ten and Cy's rises to ten. Nothing clinks, but Cy grins all the same. Maya cannot send more than her note shows, because the board stops her, so a line never drops below zero. Each wallet has a lock-code, a secret that only Maya and a grown-up in her family know. It is not for friends, not for strangers online, and not for anybody who asks. On a phone the board becomes an app, a small screen of notes. It looks different but works the same. Before sending, Maya checks the name twice, because a send is hard to undo. A grown-up sets up the wallet and helps with any big send.
1
At the Wallet Board, what does Maya's line show?
A pile of coins she can touchA note of what is hersA coin that travels along a wire
2
Maya has 20 and sends Cy 10. Look at the table. Then Maya's note says .
3
On a phone, the board becomes an app that works a different way.
TrueFalse
4
Maya's note says 20. Circle every send the board would allow.
Send 5Send 20Send 25Send 12Send 30
5
Maya and Cy each have 10 now. Together their two notes make .
6
Maya sends Cy 10 and nothing clinks. Why not?
The keeper just changes two notesThe coins are very quietCy was not listening
Match, order and fix
7
Join each one to its job.
1Lock-code
2The board
3The app
4A grown-up
Aa small screen of notes on a phone
Ba secret only the family knows
Cstops a send past your note
Dsets up the wallet, helps with a big send
8
A friend asks nicely for the lock-code. It is fine to tell a friend.
TrueFalse
9
Circle every safe habit.
Check the name twice before you sendTell a friend your lock-codeKeep the lock-code to yourself and your grown-upSend without looking at the nameLook at your note before you send
10
Number what happens when Maya sends Cy 10.
Maya sends ten to Cy
The keeper changes two notes
Both notes say ten
Maya checks the name twice
11
Cy says: the board let Maya send 25 from a note of 20. Which fix is right?
Notes can drop below zero, so it is fineThe board lets anyone send any amountThe board stops a send past the note, so Maya can send up to 20
12
Stretch: Maya has 20. She sends 5, then 5, then 10. Her note now says , and the board stops any more.
13
Write one thing you check before you send, and one job that belongs to a grown-up.
14
Draw the Wallet Board with Maya's and Cy's lines after Maya sends ten.
Scan the code at the top to mark this sheet on screenTake a photo of your answers or type them. It is marked for you automatically, and your score is kept.
Answer key · Set A
Digital wallets and apps
1A note of what is hers The number is not coins to touch. It is a note of what is yours, called a digital wallet.
210 20 − 10 = 10. Her note drops by 10 and Cy's rises by 10.
3False The app is a small screen of notes. It looks different but works the same: notes change and coins never travel.
4Send 5, Send 20, Send 12 The board stops a send past what the note shows. 25 and 30 are more than 20. Sending all 20 leaves zero, never below.
520 10 + 10 = 20. The same 20 as before: no coin was made or lost, only the notes changed.
6The keeper just changes two notes No coin travels anywhere. The keeper changes two notes: Maya's goes down and Cy's goes up.
71-B, 2-C, 3-A, 4-D The lock-code is a family secret, the board keeps every note honest, the app shows the notes, and a grown-up sets up the wallet.
8False A lock-code is not for friends, not for strangers online, and not for anybody who asks. Only Maya and a grown-up in her family know it.
9Check the name twice before you send, Keep the lock-code to yourself and your grown-up, Look at your note before you send Checking the name, keeping the code private and looking at the note are safe habits. A send is hard to undo.
102, 3, 4, 1 Check the name first, then send, then the keeper changes two notes, and last both notes show ten.
11The board stops a send past the note, so Maya can send up to 20 The board keeps every note honest: a send cannot go past what the note shows.
120 5 + 5 + 10 = 20, and 20 − 20 = 0. A line never drops below zero.
13Your own words: a grown-up reads it.
Mark each answer, count the right ones and write the score on the sheet.