Remember: Digital coins are numbers in a notebook that many keep together, and they carry real risks: the value can swing, a lost key stays lost, and a payment cannot be taken back. Talk big choices over with a grown-up.
Read and answer
Read the story first, then answer.
Tallow CoveIn the harbour town of Tallow Cove, neighbors traded without coins and kept score of who owned what instead. Bram kept one big book. When Ana paid Ben three coins, Bram changed two numbers in the book. But everyone had to trust one keeper, and one book could be smudged or lost. Then Dot had an idea: "What if everyone kept a copy of the book?" There would be five copies, all the same, and no single keeper at all. Each notebook listed every neighbor's coins: ten, eight, six, four and two. Then Ana stood up and said, "I send three coins to Ben." Everyone wrote it down, so Ana now had seven and Ben eleven. But Cy had a sneaky thought. He changed only his own notebook, so that beside his name it said sixty instead of six. Four notebooks said six and only one said sixty, so the many outvoted the one, and Cy's sixty was ignored. To send coins, you show a secret key that only you hold. Digital coins work the same way, as numbers kept in many shared copies, and they carry real risks.
1
Ben had 8 coins and Ana sent him 3. Ben now has coins.
2
Ana had 10 coins and sent 3 to Ben. Ana now has coins.
3
Cy writes sixty in his own notebook, but the other four say six. What happens?
Cy's sixty is ignored, since most copies say sixEveryone must change to sixtyCy owns sixty if he asks nicely
4
Out of the 5 notebooks, say Cy has six coins.
5
Join each word to what it means in the story.
1keeper
2copy
3secret key
4the odd one out
Awhat proves a payment is yours
Ba notebook of everyone's coins that each neighbor keeps
Cthe one person who decides in Bram's book
Dthe copy that disagrees with most, so it is ignored
6
Number what happened in Tallow Cove, first to last.
The other four notebooks outvote Cy
Bram keeps one big book
Dot suggests everyone keep a copy
Ana sends three coins to Ben
Cy changes only his own notebook
Think and fix
7
Circle every risk to know about.
The value can swing up and downMany people keep copiesA lost key can lock coins for goodA payment cannot be taken backA payment is told to everyone
8
The bars show how many sweets one coin bought each day. On which day did one coin buy the most sweets?
MondayTuesdayWednesday
9
Dot loses her key. Her four coins stay in the notebooks, but nobody can send them.
TrueFalse
10
Fix the mistake. Ben sends three coins by mistake. Cy says: just ask the keeper to undo it. Is Cy right?
YesNo
11
What is an honest thing to say about digital coins?
Their value never changesThey are always safeNobody promises that your coins come back
12
Stretch: Cy's notebook says sixty instead of six. That is more coins than the other notebooks say.
13
Ask a grown-up how they check a new thing before they trust it. Write what they say.
14
Draw five notebooks. Show which four agree about Cy's coins.
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
Notebooks in Tallow Cove
111 8 + 3 = 11 coins.
27 10 − 3 = 7 coins.
3Cy's sixty is ignored, since most copies say six Four notebooks said six and one said sixty, so the many outvoted the one.
44 One notebook is Cy's changed one. The other 4 say six.
51-C, 2-B, 3-A, 4-D Bram was the one keeper, then everyone kept a copy. A secret key proves a payment is yours, and the odd copy out is ignored.
65, 1, 2, 3, 4 One keeper came first, then Dot's idea, then Ana's payment, then Cy's change, which the other four copies outvoted.
7The value can swing up and down, A lost key can lock coins for good, A payment cannot be taken back A swinging value, a lost key and a payment with no undo are risks. Many copies and telling everyone are how it works.
8Tuesday Tuesday's bar is the tallest: one coin bought seven sweets.
9True The coins stay, but moving them needs the key, and there is no keeper to ask.
10No There was no keeper to undo it. A payment written in ink stays, so everyone learned to check before sending.
11Nobody promises that your coins come back The value can swing, coins can be lost for good, and nobody promises that your coins come back.
1254 60 − 6 = 54 coins.
13Your own words: a grown-up reads it.
Mark each answer, count the right ones and write the score on the sheet.