The big ideaA digital wallet is a note of who owns how many coins. Sending changes two notes.
How it works
A digital wallet is a note of who owns how many coins. At the Pebble Hill market, each person had a line on the Wallet Board with a name and a number.
The number is not coins to touch. When Maya sends Cy ten, no coin travels anywhere: the keeper just changes two notes.
The board will not let a send go past what the note shows, so a line never drops below zero.
A wallet has a lock-code, a secret for you and a grown-up in your family. It is not for friends, not for strangers online, and not for anybody who asks.
Before the send Maya has 20 and Cy has 0. After it, they each have 10.A pile of coins and a digital wallet.
👀check the name twice🔐keep the code in the family🧑🦳a grown-up helps with a big send
Three safe habits.
Example 1: Maya sends ten
Maya's note says 20 and Cy's says 0.
Maya sends Cy 10.
Maya's note drops: 20 − 10 = 10.
Cy's note rises: 0 + 10 = 10.
No coin traveled. Two notes changed.
Example 2: Sending five
Maya has 20 and sends 5.
Her note drops: 20 − 5 = 15.
Cy's note rises from 0 to 5.
Together the two notes still make 15 + 5 = 20.
Example 3: A send the board stops
Maya's note says 20.
She tries to send 25.
The board stops her, because 25 is more than the 20 her note shows.
A line never drops below zero.
Example 4: Staying safe
Before she sends, Maya checks the name twice, because a send is hard to undo.
She keeps her lock-code to herself and a grown-up in her family.
A grown-up sets up the wallet and helps with any big send.
Words to know
digital wallet
A note of how many coins are yours.
note
A line with a name and a number.
keeper
The one who changes the notes when coins are sent.
lock-code
A secret that only you and a grown-up in your family know.
app
A small screen of notes on a phone.
Watch out
No coin travels. Only two notes change.
The number on a wallet is a note, not coins you can touch.
A lock-code is for the family only: not friends, not strangers online, not anybody who asks.
A send is hard to undo, so check the name twice.
Try it
Maya has 20 and sends Cy 8. What does Maya's note say?
Maya had 20 and Cy had 0. After a send of 10, how many do they have together?
A friend asks for your lock-code. What do you do?
Why does the board stop a send that is bigger than the note?
Answers: 1. 12 · 2. 20 · 3. Say no, and tell a grown-up · 4. It keeps every note honest
Try at homeAsk a grown-up how your family keeps its codes private. Do not tell anyone a code, not even a friend.
For grown-upsThese are pretend coins and nothing here moves real money. Ask your child who may know a lock-code (only the family) and how your family keeps codes private; Digital Life has the stories about tricks that try to get one.
Open these notes on screenScan the code, or go to tutorpip.com.