Violet Challenge:  I can think of and use materials for a purpose- to build a bridge to get the mouse across the stream.

You can use anything you like for this challenge- Lego, junk modelling, playdough, straws- whatever you think would work well as a bridge.  What do these materials need to be like (what ‘properties’ do they need?) Be as creative a you like! Test your bridge once you have built it.  Place something light on it and see if it remains standing.  Then try adding something a little heavier.  Is it still standing?