The Lending Museum · ages 9-14

The Knotted Cords

The idea: where a knot sits tells you what it is worth (place value), and a total can be tied on top.

Lan runs a gloved finger down a knotted cotton cord while Beto writes the slip, with Loaf and Ledger beside them.

Read it

Who is in this book

Ledger No object leaves without a slip that says what you saw, before what you think from BackstageQuest
Lan a child of the Green Goes first; makes a friend in a minute
Beto a child of the Green Takes things apart
Loaf Ten ones squish into one ten, so a big count is tens and ones from CarryPals

Every recurring character has a short tune, so you can tell who is on stage before a word is said. The tunes play only when you tap, and the Reading Access sound switch turns them off.

The Honest Page

Which parts are true, stretched or made up — and what does nobody know?

True

Andean peoples recorded numbers on knotted cords called khipu (quipu). The Inka state used them for counts such as people, llamas and harvests, kept by record-keepers called khipukamayuq. Source
Knots on a khipu cord stand for ones, tens, hundreds and more by where they sit, and on many khipu a top cord holds the total of the cords below it. Source
3 hundreds, 4 tens and 7 ones is 347, and 347 + 125 + 210 = 682.

Stretched

Every knot on the cords is easy to read. What we simplified: Real khipu use different kinds of knot (single, long and figure-eight), colours and the way cords are attached, and they are fragile; only experts handle the old ones.

Made up

The Lending Museum and this replica are made up. Ledger comes from BackstageQuest and Loaf from CarryPals.

Nobody knows

Whether some khipu recorded words or stories as well as numbers. Researchers are still working on it. Source

Tell it back

Tell the story in your own words: who was there, what went wrong, and what they found out. Then the third loan slip, stamped, in the children's folder goes on your belt.

Ring the hammer for someone

Pick this book for someone younger. The link carries only the book, and it will wait for them on the Green.

Across the Table → For the grown-up: the story in three lines, one question to ask, and one thing to do together.