The Wobbly Garden Bridge

Ruby and Finn made a tiny garden for their toy animals. A strip of blue cloth became a stream. Two blocks held a cardboard bridge above it. Their wooden horse waited to cross. “Welcome to our garden,” Ruby said.

Finn pushed the horse onto the bridge. The cardboard bent in the middle. The horse slid towards the blue cloth. “Oh dear,” said Finn. “Our bridge is too wobbly.” Ruby lifted the horse back onto the grass.

“Let’s use a longer piece,” Finn suggested. They laid a longer strip of the same card across the blocks. It bent even more. “Longer is not always stronger,” Ruby said.

Gran sat beside them. “What could change the shape of the card?” she asked. Ruby folded a fresh strip back and forth like a fan. “Would these folds help it stay stiff?”

They rested the folded card on the blocks and tried the horse again. The bridge held, but one end slipped from its block. Finn caught the horse on the grass. “The middle is stronger. Now we need to fix the ends.”

They made wide supports from two bigger blocks. Ruby placed the bridge flat across them. Finn added tape at each end. They pressed gently in the middle. This time, nothing bent or slipped.

The horse crossed first. Then a wooden sheep followed it. Ruby counted the folds while Finn checked the tape. “Our bridge can carry both animals,” he said. “Let’s keep checking as we add more,” said Ruby.

Gran looked at their garden. “Which idea made the biggest difference?” she asked. “The folds helped the middle,” said Ruby. “And the wide supports helped the ends,” said Finn. They drew their bridge so they could remember their design.