The story in three lines. The spark takes Lan and Inkling to a garden beside a canal in Mesopotamia, about 4,200 years ago, where a girl must water every young plant before a hot desert wind arrives. Carrying jars up the steep bank is too slow; a pole on a forked post lifts the bucket but is too heavy to push. Inkling finds that pushing far from the post is easier, and Lan asks whether the post could stand nearer the bucket, so their side of the stick is long.

One question to ask. "Where on the pole was it easiest to push?" Listen for "at the end" or "far from the post." Then ask: "What did the girl add that did the pushing for her?"

One thing to do at the table. Balance a ruler on a pencil. Put a small coin one centimetre from the pencil on one side. How far out on the other side does a coin of the same size need to go to lift it? Try two coins near the pencil and one coin far away.

The grown-up layer. A lever balances when weight × distance on one side equals push × distance on the other, so a longer arm on your side needs less push (and moves further). The real shadoof, shown on a Mesopotamian seal from about 2200 BCE and still used in places today, usually hangs the bucket on the long arm and a heavy lump of mud or stone on the short arm, so the weight does the lifting. The story keeps the bucket on the short arm to show the long-stick idea plainly, and says so on the Honest Page.

Let your child tell the story back first. Telling it back is how the letter goes on the anvil.