The story in three lines. Lan and Inkling fold Kami into a hat and step into a garden in Madras in 1893, where Meena must plant eight marigold seedlings evenly along a bed and the tape measure has gone with her uncle. Lan nearly pokes the holes by eye before Mark stops her. Reading a folding drawing on the verandah, the cast fold one long strip in half three times, and its seven creases mark eight equal parts.

One question to ask. "How did they find the middle without a ruler?" The answer the story wants: fold one end exactly onto the other, and the crease is halfway. Then ask how many parts three folds made, and how many creases.

One thing to do at the table. Cut a long strip from the side of a sheet of paper. Fold it end to end, press, and open it: that crease is the middle. Fold it again in half twice more, press hard, and open it out. Count the parts, then count the creases. Ask why there is always one crease fewer than parts. If you have a ruler, check that the parts are really the same size.

The grown-up layer. T. Sundara Row's Geometric Exercises in Paper Folding was printed in Madras in 1893 and showed how folding alone can find midpoints, right angles and regular shapes, the jobs a ruler and compass usually do. He wrote that the idea came from a kindergarten paper-folding gift, the same tradition as the second book in this series, and the German mathematician Felix Klein made the book known in Europe. Halving is the fold children can check themselves: an exact fold is an exact half.

Let your child tell the story back in their own words first.