Marble Races with a cheap pool noodle (occupies the kids for hours.) Did this, but instead of cutting the pool noodle, the marble is small enough to fit inside the full noodle to roll down. Then can use the noodle for other things too!
Summer Activity and Science: EYFS DINOSAUR TOPIC: Children can help to "hatch open" the dinosaur egg using salt and tools, revealing small dino toys. Made by simply putting toy inside balloon, fill with water, freeze overnight then cut balloon away.
(Modify for tertiary) This is a great anchor chart for inquiry. Students write what they see, think, and wonder about the question. They can put sticky notes up so that the anchor chart can be used again.