a building challenge - can you build a house for one of your toys? You could use empty boxes, small pieces of wood, stacked plant pots or even twigs. Can your toy fit inside it?
make a folded paper boat - Use a piece of paper and make some folds. Can you make a 'lake' for your boat to float on? Maybe you could use a large plant pot tray or an old tub. Does your boat float? Try adding small counters or toy people to your boat and see if it still floats.
make a colourful chalky picture outside - why not try drawing an enormous dinosaur or a beautiful mermaid with chalks outside on the floor. Check with a grown up first though.